I can tell you what symptoms I had. Mine would start kinda hard when cold, would out smoke the old Cummins NTC 400 (TERRIBLE amounts of white smoke), miss something terrible, not rev over about 1250 rpm when cold due to missing, EGTs were running somewhat high, fuel mileage was down to about 15 mpg empty, loss of power.
Tom

 

Mine weren't too bad.. The engine was "quiet", it didn't have a real staccato rattle like other 12v's i'd heard.. More of a "balalalalala" than "rattarattarattaratta"

Had high EGT's at high RPM's as well. I don't remember it blowing white smoke though..

I hesitate on saying that it felt sluggish off the line until boost built, because Tim also adjusted the bands in the tranny, so maybe that helped it come off the line faster, but after the timing advance and the belt adjustment, it feels noticably stronger off-boost.