I have a 1977 Monte Carlo with a 398ci Stroker motor in it. At 60mph, with 3:42 gears in it, I am turning 2900-3000rpm. Its got a TH350 with shift kit in it. I am thinking of changing over to a 700R4 or 4L60 to lower the rpm.. Has anyone done this swap before? I know it will fit, just don't know about how the 3-speed column will work on the 4-speed tranny, torque converter selection, etc. Any help and cures for what you might have gone through would be appreciated. Billy