sounds like hes got 3 washers in the accumulator,thatll cause it to shift hard as a b***c and break alot of things,and add line pressure.did he use the hd 2 kit?my truck in one of the trannies,my mechnic had too take out all but one washer ,to get it too shift easier,and stop breaking things.also there was a thread not long ago,and farmtruck our local tuner said dont use any washers and just up the line pressure through the tune.wich it sounds like predator can do that for you.good luck hope it helps.you can break alot of things if the shiftkit is installed wrong.
mods:2004 sierra ext sb,20s ,big brake kit w,hawk pads,air bagged,2006 6.0 lq4 swap,vortec supercharged10psi, air to water intercooled w/ dual electric fans on it ,snow meth injection kit,60lbers, e-fans ,big radiator swap ,cam 218 /222 548/550 comp .hardened prs .1.85 comp roller rockers ,guideplates ,crane double springs,trans 4l65e built .pacesetter l/ts true duals w/x pipe and magnaflows,14 bolt rearend swap ,3.73s,aroemotive fuel pump system w/elec.fuel controller and bypass regulator a/n fittings, taylor 10.5s interceptor gauge,aem w/b a/f ,autometer boost/vac NELSON 93 OCTANE TUNED .