I was recently working on a Ruckstell for a friend and decided to buy a new P159 ring gear support bell housing. It turned out to be quite difficult as the dimensions of the new housing were different that of the old. The internal height was 3.586 new and 3.589 old, but the external dimensions were 4.203 new and 4.252 old. That 0.050" difference caused me lots of grief.
The new parts came from Glen Chaffin, I sure they are built to the drawings so I assume the error was in my original part. Has anyone else seem this kind of problem?
What does Glenn say about it? I'm certain a phone call to either him or Dave will produce the answer you want.
The inner dimension, 3.585 +/-0.001 is correct. For the outer dimension, Do not measure to the top of the shoulder. The housing, less the shoulder should measure 3.945 +/- 0.001. Call me if you have any questions. Glen