A too big V8, I've never heard of such a thing. I'm gonna have to Google that to see if it's a real thing.
I'm using stock 70's manifolds. I tried to get a pic, but it's a little too tight. There was a thread recently about this. I'm using the same manifolds that were recommended. Apparently they were used on camaro. If I had put the motor about 1/2 of an inch forward There wouldn't be a problem. Oh well, just puzzles to solve.