It's not a matter of holding up to the GT crank, its a matter of BALANCE. If the GT crank is not balanced to work w/ the GTP rod/piston combo then it will not work. IIRC the rod bearing (and possibly mains) are different in the GTP vs the GT motor, I would say no.
This is hurting my head. Since you say you are selling it, please do the potential buyer a favor and go get a COMPLETE LONGBLOCK from a good running motor, swap over your accessories, intake, etc. and call it done.
You will be doing this again when it grenades, which will be shortly. Why go through all the hassle of installing it just to blow it up again?? I don't understand the logic here. Either sell the car with a good motor or sell it as a rolling shell and move on. Nothing good will come of this.
