yeah, swapping isn't an issue.. but just doing research i will need new axles also.. the pre-64 open diff and suregrips used different lengths... also need to get some different 10" backing plates for my drums.. so staying with awesome 2.89 gears for now :) I think the future will be 3.55s
I would research a "tight" converter set up if you are looking at a 3500 stall and have 2.89 gears. No cheap off the shelf converter that will slip constantly. You will be in slip/stall constantly at cruise. Lots of heat build up.