i got one quick question for you chris. I noticed that you have a 58mm throttle body but you are runnning a 224/230 cam. I have a 230/236 with more or less the same mods as you, but i still have the stock throttle body. I plan on getting a 52 or 58mm thottle body this winter...how much hp do you think i would pick up with a 58mm over a 52mm?? I ask cuz our cars are similarily set up. thank you in advance....

trav

 

I bet you'd pick up 8-12 rwhp with the 58mm TB. Even a 52 would be an improvement. Technically the stocker should flow enough CFM but I think it comes down to pumping losses throughout the system. Anywhere you can uncork the breathing a little will pay dividends throughout, all the way to the valves.

 

Did somebody say 9 inch?

I agree, don't bother with the 7.5". Do it the way GM should have done it and get a 12 bolt, or borrow an 8.8" or 9" if you can get one for a decent price.