Tranny problems???

[JTMunk]

I finally took my 92 LX to a Test n Tune today. I hadn't had it to the strip since it's build up. I had no idea what to expect for the results. I was pleased with a 12.27 at 104 for the first pass off the trailer. The problem is that the car doesn't seem to pull at all in 3rd gear (C4 trans). 1st and 2nd pull hard to 6200 RPM but when I shift into 3rd the tach stays around 5000 RPM and doesn't budge.

Specs:
347 cubic inch, Twisted Wedge Heads, Holley Systemax intake, Trick Flow Stage 2 cam (545 in 565 ex), 42 lb injectors, 70mm Throttle Body, 80mm Pro-M mass air, Cartech fuel system with -8 feed -6 return, Paxton Regulator @ 45psi, PMS, C4 Trans, PI 3500 stall converter, 3.73 gear, 28 x 12.5 ET Streets

I have not been happy with the C4 that was built by JPT in Eaton Rapids MI and wonder if this is not another problem I'm having with it.

Anyone have any suggestions? Any help is appreciated.