I have a 1999 Silverado with the 5.7L Vortec with a pair of Pacesetter shorty headers and I'm about to ditch them for a pair of longtube Pacesetters. My main question is whether I should get them with or without the EGR fitting? I have all my emission stuff taken care of so either route will be fine. I've seen the EGR plugged with a rubber seal of some sort on a 5.3 Silverado, but never on an OBS 350. Can this be done on my intake? Which would be best, does it affect the performance any?

PT# With EGR is 70-2262
PT# Without EGR is 70-2260

 

EGR won't directly affect performance any, but deleting it may give you problems with detonation, as EGR actually "cools" the mixture in the combustion chamber. We used to see problems all the time with SBC equipped vehicles pinging when the EGR got plugged with carbon or stuck closed. Drawback to EGR is carbon build up in the intake and EGR passages, but companies like BG sell EGR cleaning kits that use a chemical to clean up the carbon build up. Honestly, if your truck is a street DD, and your EGR is functioning properly and not giving you any problems, easiest route would be to get the headers with EGR provisions and run it that way. If you're looking to clean up the engine bay and want to delete the EGR for that, there's always a way to remove it. I don't remember what your EGR set up looks like, but if the valve is bolted to the intake somewhere, you could always make a block off plate out of a piece of metal and use some hi temp copper RTV to seal it off. If you have any issues with the engine pinging, you'll have to get creative and work with the timing, maybe a cooler t-stat, etc., and run it the way we used to before EGR was even a concern.

 

Wrong part number for a 5.7 unless you have a LS1 swap. Those won't fit a tradional SBC head.

 

You sure? Summit could be wrong but it clearly says 96-99 5.7L Suburban, Tahoe, Yukon. It should bolt right up to my truck as well. I could be wrong but I may call Summit tomorrow.

WITH: http://www.summitracing.com/parts/PSM-70-2262/

WITHOUT: http://www.summitracing.com/parts/PSM-70-2260/