rear dif swap?

!@#?fiat · Post by **!@#?fiat** » Tue Apr 25, 2006 10:06 pm

Hello, i have a friend in need of a rear diff repair in his 82 spider 2000. i am needing to know if a 77 model spider rear diff center section will interchange?

So Cal Mark · Post by **So Cal Mark** » Tue Apr 25, 2006 10:49 pm

they will interchange, but with a couple of changes. The driveshaft will need to be changed also as well as the panhard rod. It's also going to be a different ratio

!@#?fiat · Post by **!@#?fiat** » Wed Apr 26, 2006 1:29 pm

Do you know if the ratio will be numericly higher or lower? 4.10 ver 3.73? Thanks

So Cal Mark · Post by **So Cal Mark** » Wed Apr 26, 2006 3:43 pm

your 82 should have a 3.9, the 77 should have a 4:3 but it's not uncommon to find rear axles already swapped around. So who knows what's in there now

bandit · Post by **bandit** » Wed Apr 26, 2006 4:01 pm

4:3 will raise your RPM over the 3:9

Dan

!@#?fiat · Post by **!@#?fiat** » Wed Apr 26, 2006 9:45 pm

Well i will check them before i install or swap them. 4.3 would be nice for some short track hot rodding around. What about the 79 model spider? will it have a 3.9 gear? I have one of those also, and would perfer the 4.3 gear in it. The 79 has a 5 speed and don't think the extra 10% would really hert me on the top end. It could use some help in the speed department

bandit · Post by **bandit** » Thu Apr 27, 2006 6:10 am

yes 79s come with 3.9

Dan