egr or no egr ?

  After finding out I have a numbers matching car with the help of great people here on this site. I want to put the car back to the way it came from the factory. Where I'm confussed is there is no egr valve or emission equipment on the motor.I think some of it was takeen off to install the headers,however where the egr valve gose there is a plate bolted on and it looks like it came from the factory that way(the cover is painted  and it matchs the engine color) So my question is in 75 did all corvettes have egr valves.

Yep, egr was used on 75s. I got the same plate on my black 79 with headers. I put it on there myself. EGR is in my box-O-parts. mkapp78792008-01-18 19:19:32

MIke is right...your car should have the EGR on it. I wouldn't bother installing if you have headers on it now. I'd wait until I put manifolds back on it(if that's what you're planning), and do it all at one time.

This post raises a question for me. My 76 has the EGR with headers on it. The EGR has 1 nipple with a hose running to a nipple in the front of the intake manifold next to the thermostat housing. Is this routed incorrectly ? The reason I ask is in reading the previous post indicates that stock exhaust manifold versus headers make a difference. This would not have any bearing in the way that my EGR is routed. Tuxblacray2008-01-18 20:34:11

The EGR will still operate with headers. It's basically a valve that allows heated air into the intake. In my case, when I installed the headers, I pulled the AIR pump and system, the EFE and just figured I'd pull the EGR, too.

You can run the EGR with headers...it just doesn't operate as efficiently to do it that way. The idea of the EGR is to re-route some of the burned(inert) fumes back into the intake, to help lower the cylinder temps to keep detonation(pinging) from being a major issue, AND reduce emissions.
Headers lower exhaust back-pressure, thereby reducing the amount of inert exhaust going back into the cylinder. It does still work...it doesn't actually hurt anything that I know of...just not sure if it is worth the extra heat on/in the intake manifold. Sorta a "benefit VS downside" thing.
I personally would not run an EGR set-up with headers, but it's just a preference of mine.

Well crap I am going to have to go to the speedshop to get a definative decision made. I originally thought the EGR would be a good thing if I ran it because in design it would do as Joel said.

That was before I thought about how my hoses were routed. At this point I don't think there is much value to it. But need that boast of reassurance.

Fortunitly I have both styles of Edlbrock Performer Intakes in my garage. 2101 non EGR & 3701 EGR.

I know that I can slap on the 3701 and it will run fine because the current stock intake runs fine. question is will running the 2101 and removing the EGR will it run better or will there be no noticable change..... Tuxblacray2008-01-18 21:24:26

You won't notice any difference.

Thanks Mike, Between your and Joels advice I think I will go with the 2101. If for no other reason it allows me to remove some hardware and a hose to give the intake a cleaner look.