Bad Purchase Story along with Question CM870

[Smooth]

Before my question thought would share the horror story one of my customers have stepped into.
This customer jumped in Trucking head first buying trucks left and right etc with no experience. They got one hung in them, 06 Intl 9900, CM870 430K miles (Yea Right), dolled up new Wheels, New Chrome Grill, New Bumper ( Put on backwards by the way) , new chrome mudflap hangers the works. Shitty Motor paint and Oil all under the Cab where they failed to even look paid way to much for what they thought was a jewel..... Turns out Cams gone, had a liner eat up, so complete in frame, ECM slapped on it from a junkyard at some point with a different ENg # in it.

But anyhow to my question..... I ran several 870's my self none are de-mandated simply EGR unplugged,, Customer is dead set on de-mandated engine.. I recall reading somewhere about not changing ECM in 870's that Cal**rm has a conflict with 870's. Asking if any truth to this or any other information.

Familiar with making changes to 871's but never changed anything in a 870.