i know there are a couple different rears that the 7's came with. like 4.10 and i think 3.9. what are the others. and what do the different numbers mean. the reason im asking is because im buying my cuzzins 7. it has a rebuilt tranny and a 4.10 rear swapped from a gxl.

Check out these two web pages for some info that may help you....



RX7.com



Mazdatrix



Both will tell you what came in which model and year. RX-7.com provides some additional information.



I will try to track down even more for you.

thanx dude . awesome

so wait.. it doesnt mean anything that he got a 4.10 rear in there. so its the same as what i have in mine now??? so all 86-88 diffs. are the same? to check if it has an lsd i know there is a way to checkwith jack stands and spin one of the wheels. how do i tell if its an lsd. both wheels spin if its an lsd right?

All 5 spd FCs came with 410s but the GTUs. That came with 430s.

No. Someone correct me if I am wrong here, but the other wheel should spin the opposite way.

the easiest way to test an lsd is to hold one wheel and spin the other. if there is resistance and once it starts moving gets easier its an lsd. if it just spins freely its not an lsd.