well that 1 of 2 things actually

the other that could cause that is the low/rev clutch pack assen not being installed properly if this is a rebuilt unit u may want to check that... remove the trans completely remove the input speed sensor grab a flashlight and look inside... the steel gears on the low/rev clutch assem should be visable and directly in the center of the input speed sensor's opening. if not that clutch pack has to be removed and rebuilt... due to the fact that the pump was installed with the clutches no seated properly bending the gears on the 2 input clutches on the outside of the clutch assem. pretty ez actually. but those r the only reasons the trans will not spin when installed to the block under proper tourqe.

(this reason and the one i stated above)


Jake


mods include but not limited to:
engine: AEM cai , pp head / TB / intake runners, Chikira 4-2-1 header , custom 2.5" exhast / pacesetter high flow cat/flowmaster2 muff,1mm over sized SS valves,PT valvetrain, AEM cam gears/pully set, prothane motormounts,440 injectors , ground kit.
Trans: Custom ATX (1 of a kind) poly-graphite steels , kevlar clutches , final drive , shift kit,3500 stall TC, Tourqe Wonder trans chip ($120.00 2gnt price only!!email for order info)