Originally Posted by signature600

It's not the mechanics of one with the electronics of another...it is the head of one pump mated to the rotor of another!!!

You get the bigger plungers (7.5mm vs 7.0mm) of the SO pump, with the higher pressure of the HO pump. That in itself might create a little timing bump, but shouldn't be that much...the electronics will limit the timing advance.

BUT...is the truck having problems an original HO??

If the static (mechanical) timing of the HO's are higher (which they are), then you go putting the bigger plungers in the pump, it will advance the timing a bit, because the injectors will pop sooner from having more volume (bigger plungers) Add to that the dramatic dynamic timing advance from the Smarty, and you could run into some problems in some trucks...I don't think all of them because as some BOMB's have shown, every truck is a little different!

Just shooting from the hip at this point...I'm just talking Some of this might be true, but I'm defiantly not an expert
Chris