Will those Trick flow aluminum 23 degree angle heads fit our TPI engines? Will the intake bolt up to the heads without any problems. Can i use the stock standard size pushrods. Also how well do they perform and maybe a cam recommend that works well with these heads.

1991 Z28 1LE 5.7 Auto.

 

I forgot are they emissions legal meaning do they have a provision for the egr.

 

TFS makes 87 and up heads as well as 87 and older heads (for intake manifold bolt pattern). Just pay attention to the part numbers when you order. AFAIK, all of them have EGR provisions and are emissions legal.

Pushrods depend on what kind of rocker you use and if you install guideplates. If you use SA rockers, you can reuse the stock pushrods.... I wouldn't do it, but to each his own. If you use non-SA rockers, you will have to install the guideplates, go to hardened pushrods, and depending on the rocker you use, you will have to get a different length pushrod than the stock ones to keep the geometry correct.

Pretty much any camshaft will work with the TFS heads. The max lift you can run with the heads depends on which ones you buy as some come with better valvesprings than others. I went with the intermediate valvesprings that handle .540" lift and am using the LT4 HC with 1.6 rockers which makes .525" lift. It works well but more lift is always a good thing if you have the piston clearance to run it. The camshaft should be matched to the intake manifold design and not necessarily the heads unless the heads only handle so much lift.

Also, if you do go with the TFS 23* heads, they come with a pretty comprehensive guide to what components will be needed to complete the head install (including gasket part numbers and torque specs and sequences) which lists some common sizes of pushrods to use with different rocker arm manufacturers. The little guide that comes with them is very helpful .

Hope that helps some,
Matt