hi
what size differental does a stock 85 gs 12a have?
Don

 

Standard Mazda 7", just like RX-2, RX-3 SP, '94-up Miata, and the front of some trucks.

 

The 85 Rx7 (GS, GSL, and the GSL-SE) will have the larger axle rear ends. You can tell by measuring the housing around the wheel bearing. If it is close to 3 1/4" it has the larger axle. If it is about 2 7/8" it is the small axle. The key thing is if it is a GSL-SE, which has a different length axle (for the added offset) and a different bolt pattern. You can use the third member from a GSL-SE in any 84 or 85 Rx (and it has a slightly lower gear ratio).

Hope that is helpful

 

who makes the aftermarket?
what i'm looking for is a little quicker 0 to 60
any suggestions?

 

Check out members.aol.com/solomiata and look under drivetrain information.

 

thanks Peejay

 

You can also contact SelectMaz in Austrailia for a great price on used ring and pinon sets.

 

go for a gsl-se swap,

you will get bigger gears and an award winning lsd

check out my write up on it

click me

 

GSL-SE only has 4.08 or so gears - not really worth the swap IMO. They're not any larger either - same ol' 7".

I say scrounge some 4.30's or 4.444's out of a Miata or 4.778's out of a Kia!

 

Kia - any contact details please.

I am still after a 5:1

Thanks

 

Ya, Peejay, can you tell me more about the Kia swap?