I saw on SLP's website a modified pin or something they say you need to install 4.10's with the Zexel Torsen locker. What is it and do I need it? I've done gearswap's before but not with this type of diff and I was going to order a set of Richmand gear's from Summit but I don't know if I need this special set up from SLP and would rather not spend more than I have to on the 10 bolt knowing I will eventually upgrade to a 12 bolt. Does anyone know why this is ?

 

the cross pin will not clear the ring. A 410 ring is deeper on a 7 1/2 diff, and, the torsen square cross pin must be split to get it to clear. You can machine one yourself (just like the original but 2 piece), or buy from slp (expensive).

 

Does the cross pin just need to be cut in the center to shorten it equally on both side's? Can I just take a wizz wheal and take a 1/4" or so out of the center, or does a new pin need to be made but only shorter, or is it more involved and worth it to buy the kit from SLP for $170? I know that they are very expensive and would rather modify it myself... If you know what need's to be done please let me Know!

 

The cross pin cannot have a gap in the middle. Because it is a C-clip type of retainer, no large clearance can exist. Otherwise, the axle can move and the clip(s) would fall out. Two halves could be made from 4340 stock with the same distance as the stock. I would heat-treat this by oil quench from the austenite tranformation. It should provide sufficient hardness for contact with the moving axles. Or, just purchase a Moser 12 bolt with a tru-trac and 33 spline axles. I run a D1/ 383 and tore the stock to pieces. A larger ring gear is alot better on the drive line. I installed a Moser 12 now.
Good luck!