If not what are some good heads to get with an LT4 intake? I'm building a 355 with forged internals and I was going to try and get away with using an LT4 intake and port matching my heads. Also will the LT4 vavle covers work on LT1 heads? Thanks

-James

 

Im pretty positive the runners are different on the lt4 intake/heads vs. lt1...they are not interchangable. Having your lt1 castings ported by someone like Lloyd or AI and then having the intake gasket matched would be your best bet for the $$. Also, the lt4 vavle covers will work.

Aaron

 

There is an interference between the LT4 intake and the LT1 heads on the rail that supports the valve cover. Either the head or the intake needs to be machined for clearance.

Is you LT4 intake already "ported"? If so, to match what heads? If not - just "stock" - it offers no advantage over the stock LT1 intake. I wouldn't let the manifold issue dictate my head selection. The LT4 intake is really only useful if you need a high flowing intake to support LT4 heads, and even then it takes a substantial amount of work to get it to flow correctly.

Surprisingly, although the LT4 heads have 0.100" raised runner ports, GM never bothered to provide the same port openings in the LT4 intake. They just put a lot of extra meat at the top of the prot (hence the intererence with the valve cover rail) so that the LT4 could be ported to match the LT4 heads, if the spirit moved you.