Cm870 engine brake

[Chamberpains]

They hold better than any ither engine I've ever driven by miles and should be exactly the same if not slightly better than the cm871's.

My cm870 will hold 80,000 at 45 mph (8th gear @ 1700 rpm) on a mile long 9% grade pushing 31+ psi. I may have to lightly pump the brakes twice to lower rpm's and give the engine a rest. But that's just me being kind to the engine. I imagine I don't have to pump the brakes at all.

If I'd go down to 7th or lower it'll hold whatever speed I desire as long as the RPM's are 1500 or higher.

Haven't you posted before that your dad has problems with boost pressure, the turbo or something of that nature? Who did the tune on his truck? Is it verified good?