Actually, the shorter 3 speed was the heavy duty 3 speed. The longer one is the standard version. I don't think you will be able to tear up the HD 3 speed with a 261 unless you are running drag slicks on a heavy truck and winding it up before dumping the clutch. Lord knows it would be tough to power shift a column shifter. I had a fairly healthy 235 in front of HD 3 speed and it never gave any problem.
