OK, this may be a dumb question but I figure it's easier to ask here than try to hunt down the info in my Haynes manual. I just got a new Performer intake manifold with the EGR provision, as well as a new set of intake manifold gaskets for when I install it. The engine is a federal emission equipped GM crate 350.
<font color=red>The question is, are there supposed to be holes in the gasket for the ports from the EGR valve to the head?</font color=red> Seems like there should be, but nowhere in the documentation for the gaskets or the intake does it mention modifying the gasket. I'm sure that this will be obvious when I actually remove the current intake and look at the head, but I don't recall cutting holes in the gasket when I installed the manifold that's on there now. It's quite possible that my EGR is inoperative now if the gasket needed holes cut in it.
<font color=red>Also, my EGR valve looks like it's seen better days. Is there an easy way to test it, or should I just go ahead and replace it?</font color=red> I've heard that there were three different types used on '78 GM vehicles - positive backpressure, negative backpressure, and vaccuum operated. I assume that mine is of the vaccuum variety, since there is a vaccuum hose running to it from a little doohicky screwed into the water passage in the front of the engine. A vaccuum hose runs from this doohicky to the carb. I assume that the doohicky in question is meant to control the vaccuum applied to the EGR depending on the temperature of the engine.
Sorry for the dumb question, but this is the first engine I've ever torn into that is not smog exempt. Thanks for any help.
<font color=green>Evan</font color=green>[img]/wwwthreads_images/icons/crazy.gif[/img]
<font color=red>- Contagious Off-Road -