there are machining and or a spacer to be made to fit any gear set into our car other than the 307 or the 327,, then you have to set it up,backlash and such. at the time double had his rear done,,,I think it is out of a 190 it is not strong enough for the crossfire,, as you know i have done a lot of research on diff, well none without Rudy and Rob. when i say i can build a 3.46 for you what i am saying is Rudy and I will build you a diff. we tried the 190 about 14 months ago,, with my V8 i blew it up in lass than 1 mile ,,the second burn out it exploded and there are other gear sets that will fit but i and Rudy are only using ones that we know should work and last 3 to 400,000 miles. hope this helps everyone understand the diff for the crossfire.