Emissions Control Questions

[cstephl]

I own a 85 GMC C1500 and a 86 Chevy K30. I am new to this forum and look forward to sharing some technical information.

My 85 GMC C1500 W/ 305 c.i./turbo 350 currently has the heads removed due to an internal coolant leak which turned out to be cracks at the exhaust valve seats on 3 combustion chambers. I am replacing the heads and also the intake manifold which has a crack between the secondary ports below the carb base.

We have no emissions testing in my area, so as I go back together I want to eliminate unnecessary emissions controls. My pickup has UHK emissions controls from the factory which includes AIR and EGR systems.

I have already disconnected the AIR system. There are quite a few rigid vacuum lines with leaky fittings going all over the place to different gizmos in the rest of the emissions system.

What do I really have to have for the engine to run properly? I know I need vacuum for the distributor advance, PCV valve, vacuum diaphragm motor in the air inlet, vacuum to the auto transmission, vapor recovery system, power brakes, but do I need any of that other stuff?

I look forward to hearing back from you guys.

[Highpsi]

My feeling is no, you don't need any of that other crap.

My motor that was in my K-10 when I bought it was a transplanted 350 that had a quadrajet with all kinds of once live EGR crap everywhere. The truck came with an "emission controled" 6 cyl. that had many emmissions related parts too.

I don't even have the vapor recovery canister on mine anymore. This is probably a bad idea since it vents the fuel tank obviously but I've capped the line off. Hopefully it will vent just fine through the filler neck vent.

Exhaust is simple, you could pull the factory manifolds and run headers with dual exhaust if you wanted to, that motor would love you for it.

I am not sure exactly what type distributor you have though, but a simple vaccum advance should do the trick if you have an original factory ECM controled dist.

[cstephl]

Thanks Highpsi, my distributer already has a vacuum advance. I think I will just remove all the EGR and AIR stuff that are cluttering up the engine and leave the vapor recovery system alone.

[19_Chevelle_69]

The EGR valve is actually a pretty good thing to keep. It loweres combustion chamber temperatures and helps prevent pinging and knocking holes in the tops of the pistons.

Run the vac line to a PORTED vacuum fitting on the carb.

[cstephl]

Thanks for the info 69Chevelle. You are the 2nd person to tell me to leave the EGR hooked up for those reasons. I will keep the EGR.