are all sierra CWPs interchangeable?

[CNHSS1]

i currently use sierra 7" diffs in 3.9:1 ratio, but could do with using a 4.27:1 (iirc...) from the 7.5" granada/sierra diff. i know most of the components arent interchangeable, but wondered if the crownwheel and pinions were, or if you can mix'n'match 7" CWPs to get a ratio of 4.1 plus.
cheers Gents.

[Mr2Mike]

CNHSS1 said:

i currently use sierra 7" diffs in 3.9:1 ratio, but could do with using a 4.27:1 (iirc...) from the 7.5" granada/sierra diff. i know most of the components arent interchangeable, but wondered if the crownwheel and pinions were, or if you can mix'n'match 7" CWPs to get a ratio of 4.1 plus.
cheers Gents.

Since the 7" and 7.5" refers to the diameter of the crown wheel, they are not interchangeable!

[CNHSS1]

cheers for the reply, are you sure thats correct though? id heard it was a casing measurement rather than the CWP?
if it is correct, anyone knwo where i can get different ratio CWPs for the 7" diff?

[Snake the Sniper]

I'm afraid he's right. The measurement is the width of the crown wheel. People like Quaife might be worth a go, as I know that lower ratios are available for sprinting, but I'm not too sure where they come from.

[CNHSS1]

thats fine, just my luck lol. will see who makes the aftermarket ones.

[CNHSS1]

Hi Guys, sorry to bump an old thread, but thought it may be useful for other that use the 7" diff in Westies etc etc

Bara Motorsports in Worcs area, do a 4.4:1 and a 4.7:1 CWP set to fit the Ford 7" diff, £575 and £650 respectively.
Good news

CNH