Request some help

OK, my current build for motor performer intake, perform cam, full comp headers, 1405 carb with stage 2 jets rods and springs, spin tech race exhaust, triple core radiator, full msd, 8.5mm wires and plugs car was putting out about 235whp. Transmission was rebuilt 8 years ago but was a bone stock rebuild, now that it failed and I had it rebuilt it's a b&m shift kit transmission.

Not getting this, are you saying the transmission failed after 8 years?