Building my first 460
Howdy everyone! I'm new here and this is my first post. Here's the deal. The 460 in my '77 F150 has been hinting for awhile that it's getting tired, and finally it has lost enough compression to have blowby strong enough to make a steam locomotive jealous of it's smoke. So now the new build is on.
The goal is to make this a motor that can produce enough power to easily pull a loaded car trailer (possibly with the AC on). It has to be Street able and run pump gas (87-89 octane). It will be carburetor powered without a doubt as I have no interest in fuel injection. MPG isnt really that important, because we all know that either way, it only gets 10-12 mpg at best. Also one more thing, the truck is pretty much daily driven.
I have brand new rebuilt D3 heads that have been milled .020. new valves, 3 angle valve job, seats, guides, etc. No port work has been done. Stock springs in them, but willing to change them out if needed. Stock valve train and rocker ratio. I'd like to stick with regular hydraulic lifters and regular rockers to keep costs down.
My block is a D7 casting I believe. It's been awhile since I looked, but my truck is a '77. Currently stock bore and stroke. Stock dished pistons and compression ratio. Plan is to have the block line bored .030" over, new pistons (with the dish to keep compression down to 8-8.5:1) and of course new rings and bearings. I plan to reuse the rods, but have them cleaned up and checked out. I also plan to have the entire rotating assembly balanced as well, just to be sure it's all good.
My current intake is a D3 casting 4bbl manifold that's meant for a spreadbore carb and an EGR. I hope to find a D2 or older intake, as it's made for a squarebore carb.
The big part of the equation is the cam. I had the stock one in it originally. It was a dog, even when times straight up. Never really had much power at the bottom end, but it had a decent mid range. A few years back 8 swapped in the K3500 camshaft from Summit racing. It advertised bigger lift, but similar characteristics to the stock cam. Safe to say I've never been very impressed with it. My vacuum has been lower (15" with no leaks vs 21" with no leaks), it's been gutless throughout the entire rpm range, etc. I forget the exact specs of it.
My carburetor is the Summit racing version of a Holley 4160. 750cfm, vacuum secondaries and it's a square bore.
So really I'm looking for advice from those that have built these motors for daily driver service trucks. What cam did you use? What's your horsepower and torque? Would you change anything about your build?
I've read the several guides and recipes for making decent hp/tq from these engines but wanted insight from the pros as to the all out best way to build a bullet proof street engine for this truck. The truck is NOT a drag truck or really even meant to be crazy fast. It's my daily driver and tow rig that sees a good amount of highway and stop and go traffic. Occasionally I wouldn't mind being able to stomp on it and surprise the fart can cars at the red lights.
I've got 3.23 gears in the rear end and 31" tires on her currently. Still running the stock C6 trans too if that makes a difference.
Thanks in advance!