thanks for the responses, but did yall leave the original valves in there or change them?
I dont want to get into changing out valves. If I can get a drop in retainer/spring combo, that would be great.

I plan on using 1 5/8 shorties, 2.5" exhuast, the explorer engine(inlcuding intake, injectors etc), explorer ECU, SCT XCalibrator, Pro M 77 MAF, and its going to be hooked to the 4R70W thats already in the truck.