i can get hold of a new grp a 7.5 rs500 rear diff, how much would this be worth and whats the difference, are all diffs like this the same fitment and what makes them grp a???

cheers

 

For GpA racing /Rallying a 9" Diff was used. If the Diff you are talking about has a 7.5" cwp then its a GpN diff ! These use the std v.c in various states of tension and 909 Motorsport Cwp's in various ratios. The 7.5" and the 9" share the same "shoulder " width of 7.5" tho , so be careful to get the right one . As for prices, pick one ! Everyone has their own idea what these are worth , generally too much .