So.....I love the fact I have a 300 HP RWD vehicle but am not to keen that it's not posi. Been looking around at replacement rear ends and they are of course a lot of money. Upon doing some research it looks like certain SC300/400 rear ends might work but I don't know if they are posi. My question is: will a Supra rear gear set fit into the GS housing? Or will the whole rear diff pumpkin bolt in? I'm going to my friends house tonight that have a 1994 Supra and will be checking it out, should be interesting. Anyway, your thoughts and input would be cool.

 

The whole pumpkin bolts onto the GS as long as its the 3.76 Auto TT (LSD). If you do not want the LSD effect, then you can jump to the 3.92 in the GS300, but your gas mileage will suffer.

 

why does it have to be an auto TT???? The 5 spd should have the same rear end! Why would they make a different rear end for an auto????

 

They made different rear end for the auto because the auto tranny came with 4spd where as the NA manual was 5spd. Totally different gearing.

The 5spd came with a 4.08:1 diff. Unless the original poster wants to rev high at all times, a 3.76 would be a better setup. Our OEM diff is 3.26.

 

right I knew our stock was 3.26.....I just never imagined toyota would have done two different rear ends! WOW

 

For some reason I thought the 5-speed Supras had gearing closer to the GS4'a 3.26...
Learn something new every day!

BTW, I have a 5-speed Supra diff on the way...
The car isn't driven on the freeway much, so not a big deal.
Should be a screamer light-to-light!

 

Thanks for the input guys. I do drive highway and don't want it revving ultra high but want that LSD badly.

 

IF you want to keep the OEM gearing and gain LSD, why not take a look at the TRD clutch-type LSD unit? It cost a few hundred bucks less than a 3.76 Supra diff, but you'll have to open up your housing to install it.

I'm a fan of clutch-type LSD over torsen anyways. Your preference might differ though

 

Stock gear ratio on 20s is a monster on the highway and saves big on gas.
you can swap the LSD from a supra, you do not have to get the whole diff.
However; unless your doing everything your self (work), I recommend going with TRD. It will be cheaper in the end.

 

Well, I found TRD Supra rear diff out of Japan but they never said what the gear ratio was and probably won't know. I'd prefer to keep it as highwayed as possible since feeding that 4.0 liter is spendy.