Hey guys. I'm kinda new to this forum so please bear with me. Now, normally, I've been a ford guy all of my like until recently, my dad's chev truck tooked too tempting for me. I realize that this is a ford website, but I've yet to have any success in any other. It was a 1980 silverado diesel-gas 1/2 ton coversion with a 455 olds in it. Anyway, the truck sat for too long and even as I baba drove it, the engine didn't hold up (piston #2 completely gone.) Now, I'm building up another 455 to replace it with my uncle and just wanted a second opinion on what kind of performance I should expect out of it. We are putting in edelbrock intake, 750 carb, timing chain, cam and sprockets as well as high volume oil and gas pumps. He said that even a stock 455 has no problem laying rubber, so I expect this thing to do a smoke show fairly easily. Also, I have a friend with a 400 in his halfton who I want to race. It has a cam on it and was dynoed at 325hp but has lots of torque. It will be a 1/4 mile race. His truck has (don't quote me) 338 gears while my rear end speed is really low. Sorry for the long post but I am pretty desparate to get some feedback on atleast one of these forums.

 

Well at least it's not a chevy 350.

Anyway, not knowing anything about either engine, I'll make some basic recommendations that should apply to most motors:

Take the heads off and port them. Dont go nuts grinding metal, but smooth things out and round things off. Remove any machining marks in the valve bowls, and be sure to smooth out the short side radius. Trust me, it helps. Plus, dont tell your friend about it.

Use thin head gaskets for a bit more compression. Steel shim gaskets coated with copper spray a gasket is usually the best.

If you're going to put a cam in it, get a good one. Match it to your compression ratio. Think Crane or Comp.

Run headers if available, dual exhaust, and a good size 4 barrel carb. I dont know what size, but I think a 750 vacuum secondary would get the job done. So you're on the right track there.

Put some good gears into it. 3.73's would probably be good. But, if it's already got 4.10's, then let it go at that.

Last but not least, sell it and buy an F100! (hey you had to expect that!)