Having a few problems with gearing on my Eagle RV Jeep style kit due to much bigger wheels than standard: 215/80/15, running a 3.89 7" diff
I bought a 4.7 crown wheel/pinion but it does not fit the diff assembly because it seems too big, although I'm assured it is actually from a 7" diff not a 7.5"
I also bought a Granada 4.27 7.5" diff, which is bigger externally of course - and it's looking more difficult than I hoped

So questions:
Why should the 4.7 7" crown wheel not fit the diff?
Is it possible to convert from 7" to 7.5" diff without having to re-engineer the diff mountings on the rear suspension?

Thanks for any advice

Well I got a few interim answers:
1. Seems my diff is a rare 6.5 incher.. I have read that those are externally identical to the 7" ones
2. Looks like the 7.5 inch diff mountings are further apart than the 7" ones, so it looks unlikely that it will just slot in where the 7" one is

Luckily the 6.5" has never been fitted to the car. It was an additional one obtained in order to speed up the job without disabling the car for too long.
I hope the one actually fitted is a 7" type

[Edited on 21/8/17 by spegru]