Gear swaps between cases

That would be a really good thing, I wasn’t sure if they would possibly be the same as when six states built the driveline for us they asked if we were running a big pinion or small pinion so I just figured it would make a difference. I’ll take some measurements and let you know what it looks like. If it’s all doable then the answer will be swapping the sure grip into the 741 to get the 3.55’s. Of course I did see that dr diff has sure grip units in stock. Maybe the better answer is to get one of those and have a couple sets of sure grips.

To add to the info that Roy posted above, here's a pretty good guide to the 8 .75 differentials that Ma Mopar has used over the years.

Guide to the Chrysler 8-3/4" rear axle - www.Mopar.nl