: If I were you, i'd try the 3:64 first.

: : : : : 5-sp out of 81 320 have rear carrier and speedo also
: : : : : should i leave in my stock lsd rear or put in the 81's for proper speedo reading would prefer to use the 79's 3.64 gearing opposed to 81's 3.90?

: : which rear will give my 79 a proper reading thanxs