i have a 85' gsl 5-spd and a 84' gs with an auto trany can anyone tell me what the rear end ring and pinion gear ratio is with the automatic trany ive heard its lower (searched, but if u can find it point me to it)

 

3.90 for the 4 speed
4.11 for the auto

 

3.909 for ALL FB's. This goes for both 5 speed and Auto. (Except GSL-SE)
4.083 '84 GSL-SE
4.077 '85 GSL-SE

The trannies are different though.

Here's a good post (I hate "quoting" myself)
https://www.rx7club.com/showpost.php...0&postcount=14

 

yea i parted out an auto and the diff was just the normal 3.90