Recently bought a 75 Jeep J20 3/4ton, originally had a 401/TH400 and quadratrac, 37" tires. I want to do either a 4bt swap or 6bt. I have a line on a complete 6bt with 5speed and tcase out of a dodge ram for $4000. The 4bt will be quite a bit more difficult to piece together. I occasionally like to go offroad. Which should it be 4bt or 6bt?