I just wanted some more clarification about 72 degree center intake bolts on the manifold. I have my stock 85 Iroc's TPI manifold and it bolted up fine to my LO5 350 that i swapped. I'm going to be buying new heads and I keep hearing different things about what determines 72 degree center bolts.

Here are some pictures of 2 bolts that I threaded into the heads to show the difference between the center intake bolts and the normal outside ones:

http://s26.photobucket.com/albums/c1...t=DSC_0164.jpg
http://s26.photobucket.com/albums/c1...t=DSC_0165.jpg

If I were to order new cylinder heads that are NON-72degree center intake bolts, would I have to do anything to my stock '85 TPI base? THANKS!

 

The heads you showed in the pics definitely have the 72 degree center bolts. Are you 100% sure that your intake base is an 85 model? 85-86 motors used the standard 90 degree angle on the center intake bolts. F-body cars switched to the 72 degree angle in 1987. Corvettes kept the standard 90 degree angle from 85-92. If you actually have an 85 f-body TPI intake on your motor, I'm surprised you were able to bolt it to those heads without having to router the center holes out a bit.

 

You are absolutely correct and after looking over the motor last night with a friend, we came to the same conclusion. My old 305 is NOT stock. The heads on it also match the 72degree intake base, so that is definitely not from 1985. Just to reinforce this conclusion, my old 305 is also a Roller cam block...and apparently those weren't in Fbodies from 1985-86 either!

 

That's pretty sweet dude! It was nice of the previous owner to throw a roller motor in there for ya! You're ahead of the game with your particular 85.