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Discussion Starter #3
Thnx... I have a 73 Clevland, 67 FE and 'am looking at another FE.
It is in a 72 pick up, has 50k since a .040 over rebuild.
I don't know anything about the heads.
 

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You have to really watch out assuming heads from various years have or don't have induction hardened seats particularly with engines like the 460 that was used in passenger cars and light trucks because it all depends on what emissions package the engine used from the factory...

For instance, I had problems a long time ago on a rebuild that I did on a 1978 Ford F350 pickup with a 460 engine. We bored the block, valve job'ed the heads etc, it was a nice engine. The guy ran it about 2000 miles and it dropped a cylinder. It came back, no compression so I pulled the heads back off and found that nearly ALL of the exhaust valves had sunk into the heads, no seats left, some were down about .100(cyl with no compression) I couldn't believe it! So I put some hardened seats in the heads, redid the valve job, put it back together and the guy ran it another 100,000 miles...

It turns out that the F350 was intended to use regular fuel not unleaded in 1978 and thus it did NOT have induction hardened seats. What I think happened was that early in it's life it was run on leaded fuel. The seats became surfaced hardened and looked pretty good when I too the heads apart after many miles. I ground the seats(took away that surface hardening) and then running on unleaded from the start killed the seats very quickly..

My 1979 F350 does not say "unleaded fuel only" anywhere on the truck and I would bet the original 460 engine did NOT have induction hardened seats.

Why Ford would bother to not just induction harden all of the exhaust seats after catalytic converters became commonplace and unleaded fuel was in use is beyond me...
 

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That is a very good point Dave. I have a 79 F 350 non catalyst truck as well and motor with a build date of late 78. When I took the heads to have them done, I asked about the hardened seats. I came back when he ground them and he assured me they were induction hardened. My truck has the big gas filler necks as well and those are the reasons I bought it. So I do not have to fool with convertor and smog equipment. Truth be known I still worry about the seats... If they go bad, it will give me an excuse to go to a larger valve size.

I guess I shoud restate that hardened seats STARTED for most 75 catalyst models.

I remember reading before that you towed with your truck? What mileage do you get?

I am loving my new motor, but mileage here in the mountains is lousy. Most of my pulls are in non interstate roads where the grades are generally steeper than interstate grades....
 

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Discussion Starter #7
My Cleveland is original in a 73 Cougar w/42k. I had never thought
anything about it. (it's my daily driver). I worry about the FE's.
Maybe, since they have miles on them, they might be hard enough if I
don't mess.
 

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it's been my experience, and dave made reference to it, that if you vehicle was used back in the old leaded days the seats seem to have gotten work hardened or something and you won't have a problem with it until you do a valve job. basically if it hasn't sunk the seats yet it probably won't until you mess with the seats like a valve job and then you better be thinking of putting in hardened seats at that point.
 

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The 351C-2V heads in the Mustang had 8 years and 2000 drag runs on them when I pulled the motor to fresh it this last winter. The heads are 71 castings with a pro valve job and stainless valves. The engine has run strictly on 91 Shell unleaded and runs low 12's (7.75 1/8 mile @ 88 MPH). The valves and seats were just fine, no recession at all. Washed heads, changed springs and seals, back on the motor they went.
 

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I do some towing with my truck almost exclusively with my box trailer that I use to haul my band equipment. It's a small single axle trailer that weighs about 3500lbs. My truck weighs about 5200lbs with no driver and it gets about 12mpg on the highway running 70mph. It does much better if I run slower and worse if I go faster, it has a 4.10 rear axle and even with a 31x12.5 tire it's over geared. I think it would have an easy time pulling a 3.50 gear ratio on the interstate.
 

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Falcon67 said:
The 351C-2V heads in the Mustang had 8 years and 2000 drag runs on them when I pulled the motor to fresh it this last winter. The heads are 71 castings with a pro valve job and stainless valves. The engine has run strictly on 91 Shell unleaded and runs low 12's (7.75 1/8 mile @ 88 MPH). The valves and seats were just fine, no recession at all. Washed heads, changed springs and seals, back on the motor they went.
But if ya had it apart, for $150.00 you could have had hardend seats put in it...........

If you do any seat work, as Dave has said... better spend the money next time, as that work hardend area will get ground out.
 

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Doing drag racing I think it would probably last a very long time before it would erode away the exhaust seat, but run it around on the street or any highway use and they will go away amazingly fast.

I had this happen to a customer one time and it sunk the seats before it burned the paint out of the exhaust ports on a fresh engine!
 
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