what is the best sierra diff for final drive and lsd

THat would depend on which engine and what you wanted to do with it

the easiest one to get is a 7" 3.62 LSD - found in XR4x4 V6's and cossie 4x4's - these arn't cheap these days though
(cossie 2wd's have 7.5" diffs with a 3.64 LSD, but these don't fit in all the chassis...)
or 7" 3.92 LSD are found in the 2.0 XR4x4's (rarer)
but then you can mix and match crown wheel and pinions to make an LSD in 3.14, 3.38, 3.62, 3.92 (& custom made ones 4.1, 4.44,.....)

or use aftermarket LSD's (quaife ATB's etc...) to turn an open one into an LSD


one thing to mention is if you want to use a ford LSD then you'll need to use bolt-on driveshafts (at least at the diff end)

[Edited on 6/1/2011 by mcerd1]

sorry should have said the engine is a 1.8 zetec 2.0 cams and supercharger on the way i have a 2.0 sierra diff fitted at the moment

do you know which type of 2.0 sierra diff you've got ?
there wasn't just one kind I'm afraid (some help here: inky )

as far the idea diff ratio goes you'd need to factor in: gearbox ratios, wheel/tyre size, the engine power band, the type of driving your doing and even just your preference

if the cars one the road already then you you'll know if you think its geared too high or too low over all (ie. are you gears before you've run out of power.....)



as for the best LSD that depends on your budget as much as anything

thanks i thought it would be easier than that but the next time im near the car i will check