on a 4t65e HD Trans, is there a way, such as using a corvette SERVO to make 1-2nd shifts "crisper" ? (other than a full "Shift kit"). Also, would I be "better off" rebuilding the 1 I have (170K) or buying a bone yard unit ? kit runs about $225, bone yard, don't know "WHAT" I end up with ?? Opinions?

Shifting can be programmed, talk to your tuner. I would rebuild the trans if it is NOT in good running order as the one you purchase may be in worse shape than the one you have.
I would assume your's has been rebuilt before.

no, this thing has NOT been rebuilt, from the fluid, I'm sure it hasn't got much left. That's why I'm thinking of doing it.(Really good Video's online of how to, all I need are the "special TOOLS.) The ECM Can be" programmed" to have a "crisper" 1-2 shift ?

quote Originally posted by Lou6t4gto: The ECM Can be" programmed" to have a "crisper" 1-2 shift ?

Yes, by tweaking line pressure, shift time, torque settings, and shift points. If you have a performance shift button then you can toggle the aggressiveness settings.
If you do NOT have the button then you can make the normal and performance options the same.

a "full" shift kit is a few shims in the shift pressure accumulators in the valvebody.. its a 40 minute project from start to finish.