Ive been putting together a 350 tpi system and just got a set of procomp 3003a heads. when i went to install the tpi intake manifold it was about an inch to narrow. When i tried to line up the original manifold that came off this same block it was the same thing, so obviously the heads require a different size manifold but what? am i dealing with vortec style heads here, i have no idea what i need to be shopping for. does any one know of any adapter plates?

 

kinda sounds like your deck height is off :S might be able to have a machine shop fab you some plates, but it prolly wont be cheap or perform well. are you sure your heads are 23 degree and not 18 degree circle track heads? some pics would definitely help with the diagnosis.

 

there are a few factors that could be the issue here. first what year is the TPI intake manifold. 87-92 model years have centerbolt valve covers and have 4 bolts at different angles in the center of the base and theres an easy fix to making these work, just use a gasket lined up the ports and other boltholes and drill at the same angle all the other holes are at. other factors are the heads have been milled or the block has been decked the fix there is take the base to the machine shop and have it milled to fit the engine. lastly i saw pro comps 3003 heads and they have a multi pattern on them and its early style and vortec style and i dont know if im 100% right but i believe you may have to get a vortec base like you would if it was a fastburn head.