Just had a professionally "Built" 4 speed auto out of a Grand National installed to replace my old 2 speed...Who Knew??
Same drive shaft, same column shift,
but a REAL Low, a Passing Gear and an Overdrive too.
BOP double bolt pattern on bell housing makes it sort of universally GM friendly, I got a lock-up torque converter, throttle cable initiates passing gear kick down, "Sweet."
2nd gear chirp from my 1 Bbl. 6 cylinder!!
Not Cheap, but it drives like a different car now!!