diffs, cr boxes, performance improvements?

[Lucozade]

Spotted a Sagaris at DrivenImage with a 3.91 diff.

Got me thinking that this topic has been discussed before but can't find much evidence of anybody upgrading/changing the diff.

I've got a late MK2 S but no idea if it's got a CR box or not.

What diffs can be fitted to the Tuscan MK2, what have others done, how much, any performance improvements ?

[GT TVR]

My 2S has a CR box and a 3.91 diff. It's my first Tuscan so I can't comment on the difference with a standard box/diff. All I can say it goes like hell and the pick up after a gear shift is very quick and smooth.
Opted for this combination since I'm coming form a very quick Griff (5.3) and I didn't want a drop in performance. Mind you my quick Griff got destroyed on the straight by John's Sag on Zolder which had the CR box and 3.91 diff. Hence ...

[glow worm]

I've got a CR box and changed from the std. 3:46 diff to a 3:73, but the real reason for the change was to change the diff flange and shorter propshaft to get rid of the diff shunt, which has worked really well. I don't do track days so didn't bother with the more agressive 3:91 option.... takeoff is good enough for me with a 3:73, provided the wheels don't spin... Paul & Heath will tell you more...they did it, with the diff coming from John Reid.