Hmmm... with your mods teh LT4 clutch might not be enough... My experience with clutches is that the GM clutchs LT1 and LT4 have no problem other than slipping when a vehicle has a lot of horsepower and torque. More than 450 at the fly could make this LT4 clutch slip. It might hold it might not.. I think i still have a number to a clutch vendor in Texas who custom makes clutch disks to fit your application. All ive heard was good things about this guy. I talked to him on the phone and hes very knowledgeable about clutches.
Do you know exactly how much hp and torque u put to the ground?
ill give u some phone numbers when i get back to my house.