ok, first yes everything is the same, just swap them out.
2nd, the speedo will be off, if you have a 87-88 then it will be off by 10 percent so 5 mph at 50 and 89-92 it will be off by 14% 7mph at 50(dont quote me on this, i think its right.)
gas mileage is also not the greatest. I put a 3.91 in mine instead of a 4.30 cause at 3k in 5ht i think it did about 60 mph ish.
your choice.