magnum and a 727

I run a manual trans PCM in my '68, and had it hooked to a 727 for about a year. You will need to use the Magnum flexplate so the crank position sensor will function and the external balancing will be correct. That flex plate will need to have one of the torque converter mounting holes elongated to allow it to bolt up to a neutrally balanced torque converter.

You likely already know you are going to have to make a notch in the bellhousing for the CPS. I used a common door knob hole saw to cut the relief. It works nicely. I put the centering drill bit for it about 1/4" from the edge and then deburred the hole with a carbide bit.

If you do the beer keg intake manifold modification and run Summit headers and an aftermarket oil pan. The stock Magnums run pretty good. If you really want a treat, buy an SCT Tuner and have someone build you a tune. Even the stock motors respond very well to reflashing. My stock motor probably gained 40 hp over stock with a reflash. I have the same PCM in the car with my 408" aluminum headed stroker with a big cam, and all it took was a reflash from a competent tuner with me giving him feedback from my wideband.