P-A-S-S-O-N No letter I in his name. That's for the OP.
Also for the OP: It's great your customer/friend/whatever is willing to take a hit selling off his kit that will work with some mods to the vehicle AND waiting for at least a year for the Passon transmission. Or did you explain that to him?
Maybe the Passon kit to convert a 4-speed to the 4-speed overdrive will suffice, but it ain't cheap either.