What options for diff ratio?

[EricYellow]

What is possible in the diff ratio department in 168mm size?
I read somewhere that with some modifications you can fit a 188 diff (the ring and pinion) inside the 168 casing?
Is this possible and if so, how does this go?
If this is possible, what is the longest ratio available in 188 size, so I can fit it inside the 168 casing?
If it's not possible to fit 188 parts in the 168 casing, what car/diff has the longest ratio in 168mm?

I've got the M52TUB28 including the gearbox but I'm shifting like crazy....

Hope someone can shed some light on this.

[anton]

Hi guys I'm looking for same information. Tanx