do i have it and what the hell is it?

 

not sure if this is what your talkin about its all i could find on it though http://en.wikipedia.org/wiki/EGR

 

i don't think you have it. it's more of a older dak one.

 

exhaust gas recirculation..... yeah i doubt you have it... those systems are a b*tch to work with on the cummins ISXs... pita

 

You don't have it... i think it was gone with after the 95+ years, maybe sooner not sure, but i know for a fact you don't have it.

and its exhaust gas recirculation = EGR, like said above.

 

there is a significant difference between these intakes on summit. both seem to be what im looking for except one is EGR and therefore more expensive. part #'s DCC-5007398AB & DCC-5007790. which one should i go with???

 

Get the one without EGR.
Your truck doesn't have and EGR. Consider yourself lucky.

 

you dont have EGR, they ended around 96, my hughes stage 1 manifold that was a customer supplied core came with a EGR hole, but hughes put a block-off plate on it.

 

Anybody else think its interesting that adding hot exhaust gas to the intake air actually COOLS the combustion temp?

 

it does actually... the exhaust gas is cooled down from all the pipe work to the intake, then once it enters the cylinder, it takes away from pure fresh atmospheric air (remember it's not all oxygen) causing less of a combustion which will cause cooler cylinder temps, less fuel used = less emissions. and to make it simple, otto engines were never designed to be compatiable with emission controls like EGR or ACCERT on the Caterpillar engines.