If you want to do a little searching, you can change the 3 gear planetary to a 4 gear by using an A-995 planetary setup, and also get the benefit of the lower 1st to 2nd gear ratio. You will need the planetary and the matching shaft, I bought mine from a local trans shop for $50. You can also get the stiffer apply lever, either the 3.5 or the 5.0, I think I used the 3.5, the 5.0 was claimed to be a very hard shift. I’m running all 904 behind my small blocks, they are much better IMO for their reduced weight. There is also talk that you can run a 66 trans, which has a front and rear pump, mine was already a 66, but you will need the matching torque converter for the larger front register of your 360, and the offset flex plate. I think you can change the input shaft for the correct spline count, or have the converter built to accommodate that.
