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'68 mustang with a 521?

17K views 25 replies 12 participants last post by  Gydyup 
#1 · (Edited)
I'm new here, but have been doing a couple months of research on putting a 460 in a 67 or 68 mustang. I've recently bought the engine, but wanted to run my build specs by you guys to see if you could give me some feedback on the streetability and any problems anybody here might have run into. Here's what I'm planning:

460 block casting D9TE (bored .30 over, dipped and zero decked)
Main girdle (I keep hearing this is not needed?)
Scat 9000 series crank (internal balance)
4.3" stroke on h-rods
flat top forged pistons, floating pin, single valve for scj heads
Ford racing aluminum scj heads (M-6049-SCJB)
Lunati solid roller cam 273/279 duration (64032SK)
Lunati double roller chain
Lunati voodoo roller rockers 1.73 ratio
Edelbrock aluminum dominator intake (2965) for scj heads; single plane
E-85 950 cfm dominator carb (demon or holley)
ford power train 2" headers for the mustang conversion
crites motor mounts
HEI distributor
High volume oil and fuel pumps

Tremec 6 speed transmission (don't have the gear ratio's)
9" 3.73 rear end

17" wheels with 315/35/17 tires on the rear

1" lowering springs
chassis stiffener
Export braces

this would be going in a 67 or 68 mustang fastback used for mostly street but some strip. There is E-85 readily available and I have the permit to make my own.

Any feedback, tips, thoughts would be appreciated. This is my first big block build and I want to get it right. Thanks in advance.
 
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#2 ·
I would think those shorty headers would be restrictive on a 521", I'd also make sure they will work with your crites mounts. I'm assuming you are using the Gen II crites mounts? If so you need to know they put the engine about 1" lower and 1" back from the older style.

If you get those headers make sure you also spec. the CJ header flange as that is what you need for the FRPP SCJ heads. You can save some money and forgo the main girdle, is not need and of no real value on a 460. I'd not use one of those DUI HEI distributors, as is really big and may cause clearance issues. A MSD distributor and 6A would work well.

I'd get a larger oil pan. One of the "T" type 7 qt. jobs be ok. Depending on what you run for main and rod clearances a std oil pump may do with the relief spring set for about 70 psi. Best pump to run is the Kaase, most expensive too...

You will need a good capacity fuel pump, regulator, lines, etc... including a return line for E85. Make sure everything is spc'd for alcohol too, as it can be corrosive. I'd think you can go with a 1050 cfm carb too.

Finally I'd consider trimming the shock towers. It is not required, but will make life much easier...

Steve

The 6 speed will require cutting the tunnel to fit.
 
#3 ·
Do you have a suggestion for headers that will work with both the scj application and the crites motor mounts (I was thinking the gen II) that would be less restrictive. I was under the impression taht I would only be able to use shorty style headers with this set up.

I forgot to mention that I intend to notch the shock towers, my bad :D

Do you have any suggestions for a manual overdrive transmission that wouldn't require modifications to the tunnel? I had been looking into some kits for the 67/68 mustangs and didn't think the transmissions from americanpowertrain.com required any sort of modification. However I'm going by heresay and what a company rep has told me, if you say it won't fit without mods I believe you guys (since you've all done it). It doesn't have to be a 6 speed, but would like at least 5 as I plan on mostly street use.

Thanks again for the great info!
 
#6 ·
The crites Gen II headers would be your best bet powerwise, but a bit of a PITA. They require a hydraulic setup for the clutch. They will not clear the stock setup. I have used them and if your car is straight they do fit. You do have to trim a little on the PS tower, but Crites tells you all about that. You should also run a late model starter from a 1993 truck as a lot smaller. Crites also says to lower the idler arm 3/4" for the PS to clear. I found using a 1970 center link clears without mods.

As for the recommendation to use the MPG kit, unless your doing a drag only car it is just bad advice. That kit puts the engine forward and up and was designed from day one for drag racing. Besides the handling and hood clearance issues, you will have no room for a fan.

Regarding manual overdrive a few things to consider. Have not heard of any T56 that will clear, if they say it will ask if the rear mount location is stock or lowered...

Some places claim you can put a TKO 600 in without cutting the tunnel, but they do it by lowering the tranmission. Some kits trim down the covers to make them fit close to right, but still have to notch the crossover support. The shifter also does not come up in the right spot, but some make a modified shifter that fit correctly.

I'm sure you know Victor and Dominator won't clear the hood. If you want everything under the hood you can use a Torker II and 850 DP, you will loose some power, but like everything else is a trade off...

Steve
 
#4 · (Edited)
IMHO:

I'm new here, but have been doing a couple months of research on putting a 460 in a 67 or 68 mustang. I've recently bought the engine, but wanted to run my build specs by you guys to see if you could give me some feedback on the streetability and any problems anybody here might have run into. Here's what I'm planning:

460 block casting D9TE (bored .30 over, dipped and zero decked)
Good.
Main girdle (I keep hearing this is not needed?)
Not needed.
Scat 9000 series crank (internal balance)
Good.
4.3" stroke on h-rods
Good.
flat top forged pistons, floating pin, single valve for scj heads
KB Icon IC861 dish pistons would be a better fit with the components you are using. It has a -22 dish and will give you a little over 11 to 1 compression. You won't be pushing the compression limit and you'll be producing plenty of torque for a street engine.
Ford racing aluminum scj heads (M-6049-SCJB)
Good. If you get them from Lem, have Charlie clean them up. Some bowl work does wonders.
Lunati solid roller cam 273/279 duration (64032SK)
That cam is too small. You'll need a custom cam with about 250-260 @ .050 on the intake side. Have Lem spec you a cam.
Lunati double roller chain
Good.
Lunati voodoo roller rockers
1.73 ratio
Go with TFS rockers.
Edelbrock aluminum dominator intake (2965) for scj heads; single plane
Plan on having port work done. If you get the heads from Lem, get the Motorsport equal and have Charlie port and massage it. Even though the TFS would be more of a bolt on installation, it's taller, and you're pressed for hood clearance.

E-85 950 cfm dominator carb (demon or holley)
Get a Quickfuel 1050 Dominator.
ford power train 2" headers for the mustang conversion
crites motor mounts
Get the MPG kit, http://www.mpgheads.com/motor_mount.php . You can get everything under the stock hood.
HEI distributor
Use an MSD with a 6A
High volume oil and fuel pumps
Get a HFD (High Flow Dynamics) street/street pump and a Mallory 140 electric fuel pump.

Tremec 6 speed transmission (don't have the gear ratio's)
9" 3.73 rear end

If you want more of a bolt-on installation (judging by your other post) get a David Kee wide ratio top loader, http://www.4speedtoploaders.com/ , and have Advanced Clutches, http://www.advancedclutches.com/ , set up the rest, including the bellhousing, flywheel, clutches, starter. A 3.00 to 3.25 rear end gear would be better. More gear than that and 1st gear will be useless.

17" wheels with 315/35/17 tires on the rear

1" lowering springs
chassis stiffener
Export braces

this would be going in a 67 or 68 mustang fastback used for mostly street but some strip. There is E-85 readily available and I have the permit to make my own.

Any feedback, tips, thoughts would be appreciated. This is my first big block build and I want to get it right. Thanks in advance.
Hope that helps, and again, IMHO.

:D

Dave
 
#8 ·
Crites have issues? Never known them not too... LOL Seems getting parts from them can take days or months. They always are behind, once in a great while they will have the parts on the shelf. They have some unique stuff, just not managed all too well. So buyer beware as to lead time, although they do eventually get it done...

Regarding the Gen II kit is a good bit different than the Gen I. Puts the engine about as low as possible, about an 1" lower and back about the same. The headers are 2" primary, do not cross over and are slip fit with a 3-1/2" colllector. They do fit with the modifications Crites states which is some minor trimming of the shock tower brace on the passanger side and lowering the idler arm 3/4". Overall I'd say is the best kit out today for all around use.

Steve
 
#10 ·
Dish pistons vs flat?

I'm sorry if I'm not understanding, but according to my calculations using dished pistons with -22 will put me under 11:1 compression. I'm using 4.39 as the bore, 4.3 as the stroke, the chamber of the scj heads is 72cc, and a gasket thickness of .089 (fel pro) I'm getting 12.7:1

I just figured out that by using a different gasket at .04 thickness and the dished pistons with -22 I'm getting just over 11:1

I guess my question is that all the cams I've looked at suggest a minimum of 11:1 compression. I'm also being told by a couple of my mechanic friends that with the 140 ft/lbs of torque on the head bolts going to 14:1 compression would be fine? Anybody have experience with all that or can explain why the higher compression would be a bad thing? I can't help but feel like I'm missing something here.:confused:
 
#12 ·
Mostly street?

this sounds like a fun ride! I also own a 67 fastback with a 521 and as my car changed from a bone stock 460 with 3:50 gears to a 521 with 4:11's, so the streetability changed to. Make sure you really want 12 to 1 compression and a dominator before you dive in. I personally would love to have 12:1 (mine is 10.6) and a dominator but I have a Honda Accord to drive back and forth to work and a truck to tow the car to the track. The 6 speed and 3:73's would definetely be better for the street but then you will be racing with a manual.

I'm not citisizing, only coaching you to make sure you know what a 12:1 compression engine with no choke and a big cam is like to drive on the street. Lots of fun on a Saturday night, maybe not so much going to work on Monday morning ( if thats your plan). I have the Ford Powertrain headers and I feel they are not big enough for a 521 used for racing.

Good luck
 
#13 ·
Thanks for the replies. I would only be driving this on the weekend for fun and hot rodding, to and from the track and down the track. I'm a police officer and therefore don't get much of a choice of my daily driver :)

After all the suggestions I'm thinking it might be better to back off the dominator and go with a 4500 series carb (I think this was suggested with the quickfuel 1050 cfm?) and the victor jr aluminum intake by edelbrock. It looks like that would give me almost another inch of clearance under the hood (just to be on the safe side), and be a little easier to handle.

Somebody also suggested the torker II intake, also something I might consider. Anybody have experience between the 2 intakes and could tell me how noticable the difference in breathing and power really is?

Thanks again, you guys are really helping me get this cemented down. I think I'm going to order the bottom end today! Going with a scat kit I think.
 
#16 ·
You have two roads you can go down:

A: Compromise for better/easier assembly/fitment, and less headache to drive and service. This would be use the FPT shorty headers, Torker II intake, 850 DP Carb., set CR at 10:1, and get a custom TKO600 modified to fit '68 Mustang.

B: As originally outlined except use the Crites headers.

A will be easier to bolt together and service. Performance wise not quite B, but still really fast!

B will be the beast both in making everything fit and play nice together, as well as how it runs.

I'd go with A if main point is to have fun and do as little cutting of the car as possilbe. Steve
 
#14 ·
Lots of opinions on engine mounts here.

I purchased a set from MPG with their headers. The reason I purchased them is I was under the impression that they set the engine where it should be to use a factory C6 crossmember, and that they can be used with power steering easily. I had heard that the Crites mounts set the engine forward and high. I contacted both companies, Crites first, then MPG. Crites were not helpful at all, wouldn't give me the time of day either by phone or email. The fellow I spoke to from MPG spent about 20 minutes on the phone with me before I purchased anything, explained all the benefits to their mounts and headers, explained how to install, and then assured me that they would be their if I ran into any problems. He then took some time to make other recomendations such as engine, water pump, radiator, etc. On the MPG site it shows the engine inside a car and it appears to have ample clearance to fit everthing under the hood.

In the end I gave him my credit card number, he explained that there would be a few weeks before the headers were ready and coated, and everything arrived home in good shape in about 3 weeks.

So, just wondering, anyone have experience with the MPG mounts and headers? Am I going to be disapointed? Thanks!

jn6047
 
#15 ·
I'd seen one a few years back, although no direct experiece with the kit. I did not like how far forward the engine was. It seems to be higher than the Crites II kit, but after looking at the article in the achive looks to be about as low as the Crites II, so much for memory. LOL

Here is a link to the article. From the article you can see it is really close to the radiator, says engine is moved one inch forward of stock FE mount location which considering the 460 is longer it is really forward. It also says it won't clear a front anti-sway bar which I can believe. My opinion has not really changed on it, fine for drags, but I would not use it for a street or street/strip car. Steve

http://i273.photobucket.com/albums/jj226/carmagguy/BigBlockTransplantpage1.jpg
http://i273.photobucket.com/albums/jj226/carmagguy/BigBlockTransplantpage2.jpg
http://i273.photobucket.com/albums/jj226/carmagguy/BigBlockTransplantpage3.jpg
http://i273.photobucket.com/albums/jj226/carmagguy/BigBlockTransplantpage4.jpg
 
#19 ·
Update

Here's an update:

Decided to go with option A (thanks steve), but with 11:1 compression

After going to machine shop and talking with the owner I'm getting and eagle cast crank 4.3" stroke 6.8" H-style rods and forges dish pistons at -22cc. They are currently boring the block .030 over and torque plate honing, align honing, zero decking, clean, dip and freeze plugs and cam bearings.

Should be a couple weeks at the shop (waiting on the pistons).

Thanks again everyone for the advice. I'll post some pictures of the block when I get it back and lay some paint on it.
 
#21 ·
I am diving in late on this, my car has been on hold since June, been building a duck boat, then broke my leg Labor Day.

I have the Gen I mts on my mock up now in a 67 Mustang, and the Gen I headers that cross over. It is up and forward, it will work but its tight and the 2 inch cowl wont come close to fitting with the Vic Intake, and spacer, it touches without the spacer.

I started building the boat while I was waiting for the Gen II mounts to be made, Crites was helpful, informative but slow.

I have not put them in yet, but I am going to see how the new location does with the Gen II mounts/Gen I headers. The Gen I stuff also was also very close on the manual steering where the back two tubes andcross over drops right behind the drag link, tons of room up front of those. Dropping down and back will be a good thing. Same with cross member. If I cant make the stock one work, I will fab up a cross member, you dont have to use it, but why risk it.

Clutches, I am hopeing to run a mech, or cable, if those wont work, hyd,.

I hope to get the outboard eng back together and on the new boat this week and get back to Proj 532 Gydyup
 
#22 ·
I have the Crites motor mounts that allow stock C6 crossmember, shift linkage, drive shaft, etc. I changed from Tubular Automotive headers to FPA shorties. My 429 is pretty mild compared to what you are planning but I do like the FPA headers. You might give them a call, Stan will build anything and knows his Fords!

 
#24 · (Edited)
I am in the throws of this right now. I have on my floor a complete set of Crites Gen I mounts and coated headers. Didnt do my homework, and thought I was getting a deal. Good stuff, fits great, BUT, hood issues, had to modify the Cross member for the Toploader, also would have to get a new drive shaft. Not to mention cant run the frame cross member. You could run a short pump and flex fan, but its tight.

I have the MPGs installed right now, jury is out. MPG is WAY more helpful than Crites, thats why I went with them. Ordered Crites Gen IIs for some of the prev mentioned reasons, the 6 weeks became 3-4 months just for the Mounts, and once you order, and pay you own them. Regardless when you get them. Jackasses.

Now for the MPG, not as bolt on as the add says, you do have to lower the idler arm, I made a slick template to do this much like the Shelby lowering templates. Also, you have to trim or notch the area or flange from the shock tower to the frame on the back side of the tower to the frame on the driver side. You cant run the front cross member.

It looks like the SBF/C4/Toploader cross member and drive shaft (I had a 3.5 Alum shaft made for the Windsor I had) is all going to work ok. I can get the eng, Vic intake, Wilson 1 inch spacer, and junk carb with a choke horn under a 3.0 cowl with room to spare. I plan on running a dominator on this one so even more room!

Got to call MPG today, I may have an issue, with the fit and steering. When the suspension is compressed or weight on, I can not turn the wheels to the right, cant get the # 8 tube on without removing the drag link, also the notch your supposed to cut, I dindt have too so I am thinking I may have one bad tube. When the suspension is relaxed (in hopefully a wheels up launch, the tie rods impact the header tube.

I did have to ding these quite a bit to clear the idler arm upper bold and Idler arm, also the boss on the Quick time bell for the cable, and starter bolts.

Will let you know, I am taking pics and will post the final yeah or nay if and when I get it all sorted out. If these dont work, I may go back to SBF. Interested to see how and how quick MPG resolves this, so far Scott has been extremely helpful, and what I like is he actually runs and races this stuff in his 67 Fastback. Crites, no help at all. They are nice folks but no tech help whatsoeverl
 
#25 ·
I am doing the MPG on a 1969 Mustang as well, with a TKO 600. In order to get #8 to clear the steering box, I have had to raise the trans tunnel all the way back to front of the seats. Had to raise the factory tunnel crossmember 1.75 inches and work from there. It looks like I am going to have to lengthen the #7 tube about an inch to get drag link clearance. Dropped the idler arm one inch. Also had to clearance the shock towers on #2, #3 and #4. I went ahead and notched the tops of the towers for clearance and also had to notch the drivers side valve cover for MC clearance. I wanted the tall FMS covers, shorter MT's would have cleared. However I think my shock tower issues could be due to the repro towers I used, they look a little differently shaped down around the header interference area. I do like that the MPG placement allows me to not cut my hood. Because of the TKO, I had to build a new trans crossmember. Still haven't put in a radiator, but it looks like I am going to have to do some fab work on the radiator support area to get it in. The headers only required some slight clearancing to the Quicktime 8010 bellhousing, but I did have to cut off the boss for the clutch cable. I am using a rear pusher hydraulic set up.

The last time I did this, I used the Crites Gen 1, with the TA headers. They worked, but were a pain and I had to do a lot of tube banging to get steering clearance. And a hole in the hood was required.

If I ever do this again, I will go the TCI front suspension set up. I nearly aborted and went this route several times on this one.

FYI, the Borgeson power steering box will NOT fit with the MPG headers, I tried.
 
#26 · (Edited)
Thanks Fordguy, I am glad to know its not just me having issues. Have you talked to Scott at MPG on this. Good guy, far better than Crites with tech help, but he keeps saying "man your car must be different". Number 7 is my guilty culprit, and he wants it back. Looks like it needs to be an inch longer and angled more forward out of the head so a more straight down drop.

Not surprised about the amount of work your having to do with the tunnel and firewall, I have heard the TKO 6 and Richmond Six speeds require a lot of tunnel work.

I dropped my idler 3/4, couldnt go any further as I am near the bottom of the frame. Dont know about 69, but there is some dimple in the frame on the 67, so no flat surface.

How does your Pitman arm clear the 6 or 8 tube? Mine is right beside it, and I dont think it will clear on hard turns to the right. But I cant tell as the current set up wont allow any turn to the right.

PM me and I will send you my email, would love to keep trading info back and forth. Especially on the clutch, I have not cut the cable boss yet, sort of thinking I may be able to use it. I liked the cable on the Small block, and I have it so if I can save the cost of the Hyrdo, I will.

Keep at it man, glad I am not the only one going this BB stick shift route.

thanks, Chris
 
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