I have the cross member modified and the 518 case installed in the car so this is mainly about the drive shaft and drive line mods.

First with the 518 case being 8 inches longer I know it will change the drive line angle so is it better to shim the differential or transmission more to get the correct angles. Either way will be easy right now because the new cross member hasn't been made yet.

If anyone has done this before for a 108" wheelbase car is 42" correct for the drive shaft length after the modification I saw that spec on another site for a A500 swap but it's 1/2" shorter.