Circle D triple disk converter, california built tranny, 13 lbs boost on a forged 390. I had an LS7 lifter that broke a roller off and resulted in an engine rebuild (hone, cut rings, all bearings, repl perf. VVT cam, dual 740 springs to 600 PAC springs, johnsons billet lifters, etc.). I did not remove the tranny nor the converter, just the engine. I found my CSR alum. flexplate cracked, so replaced with TCI 6l80 machined steel. Replaced motor mounts, one was broken. Rings still seating on engine but sounds good, but tranny now SIGNIFICANTLY slipping shifts in low gear, 4 and up shifts, TCC lock, unlock, downshift seem normal. I had about 1/16 inch clearance between TCI plate and converter when installed....usually have 1/8 to 3/16 but TCI plate and Circle D converter combo didnt permit that. I double checked fluid level is good, didnt remove any for engine rebuild. Also have since pulled pan, replaced filter, and fluid...still have same slipping. The fluid still good color and magnet only debris which seemed normal for two years of service behind 700ish hp on a 4x4. Have ohm checked two wires from PCM X1 connector to VSS on transfer case and ground 451 from PCM X1 connector.
I need help to figure out what to do next so see if I am chasing an electrical, tuning, or mechanial problem. I am planning on picking up a new oil pressure gauge this week to check the test port (my old one is so old it is unreadable now).