Here is my situation. i am in the middle of a converting my 86 LG4 Z28 to TPI, and while re-drilling the four center bolt holes in the new TPI manifold i managed to put a hole in the exhaust crossover, the passage that feeds the EGR valve. my question is do my old LG4 heads have an exhaust port @ this location or not? if they do i will have to weld up the hole i created or i assume it will vent exhaust from the intake, if not i will just leave it as-is.

heres a photo to clarify, please dont bash my poor machining, it will be functional not pretty.

http://members.shaw.ca/downfamily/TPImistake.JPG

-Zander

 

Yes they do.

Some gaskets have that area blocked or a blockoff plate, but I'd fix the manifold if it was me.