diffs

[curt powell]

would a diff off a auto be the same as a manual if they are both off the same sized engine

[Torque]

Physically? Yes, it will bolt up. edit: I should mention that the flanges might need to be swapped, but that's really easy.

However, gear ratios are different; automatics are geared lower (in other words, more revs for the same speed). Putting a diff from an auto in a manual results in faster, snappier acceleration at the expense of some increase in fuel consumption and (potentially) a loss of a few mph of top speed ... putting a diff from a manual car on an auto though ... not really recommended.