are tese new motors not trusted in U.S.A we have had trouble with signature but got isx in new trucks now

It is illegal to take an existing truck and replace the engine with an older model. What you are describing is a glider kit and it is designated as such on the title. This loophole was intended to allow a trucker to salvage a perfectly good drivetrain from his wrecked truck and get up and running without incurring the cost of a brand new truck. Of course, with the advent of the emissions engines the industry morphed into something else. Nevertheless, putting an older engine in a new glider is not considered the same as replacing an engine with an older engine.

If the legality isn't a concern, you can get the components to return your current engine to the pre-EGR state. The full package will cost about $7400 for parts, including a reprogram of the ECM.

Got the info I needed. I can get a pre-egr ISX, rebuild it, and put it in. I can send the existing firewall to engine wiring harness to Mawk Industries and they will rewire for the pre-egr engine. Total plug and play deal. Mawk can redo a wiring harnes for just about any engine to truck combination.

Came across another option that might be better. A company out of B.C. is offering reprogrammed ECM's that eliminate EGR's and/or DPF's. Can then remove EGR, cooler, and associated plumbing from engine and maintain same serial number engine that was put into the truck. These guys will reprogram or supply replacement ECM's for Cat, Detroit, Cummins that will remove function from EGR and sensors. If one wants, then can remove all the hanging equipment. Anyone interested, do a search on Ebay under your favorite engine brand/model and you should find them.