I was wondering what the differences are between an early TPI base and a later TPI base? I remember reading something about the bolts being at different angles or semething like that. How can I tell the difference between them? Do the heads heads have anything to do with it (center bolt or perimeter)?

 

Pretty much the difference is the bolt pattern based on early perimeter or later center bolt design. The intake can be machined to accept the opposite though. The aftermarket intakes are already machined to work with either style cylinder head.

 

Thanks. Just to be clear the older perimeter head design takes the older intake design & the newer center bolt heads take the newer design? Is the new design the one with the angled intake bolts or straight intake bolts. Or does that have nothing to do with it?

 

Try reading the following article. It explains the different manifolds, plenums and other parts used for the years of the TPI engines.

http://www.classictrucks.com/tech/04...ion/index.html

 

Cool, thanks