91redbarchetta

Did a V8 swap on a 91 2.3 LX. Used the 140 speedo& cable from the donor car but it reads 20 mph faster than the car is going!! Did not swap out rearend, could this be the reason for it reading faster?????

Bubba 95SN

Yes that is most likely the culprit.

Doomstein

You'll need to swap the speedometer gear on the end of the cable that goes into the tranny for one that's the correct gear ratio.

91redbarchetta

Any idea what gears are in it??? Was a 2.3 auto

Doomstein

If I were to guess I'd say 2.73.

Doomstein

Sorry about the delay.

nitrous_bob

it doesn't matter what year or motor everything was... to a point

you need to know what drive gear is on the trans (6t 7t 8t)
to know what driven gear to use on the speedo cable

but if your an auto and 20 miles off you probably can't correct it, assuming your 20 mph OVER

an 8t output shaft for sure cannot correct that much, 7t is close , 6t will for sure

check your driven gear, it's c-clipped on the speedo cable, tell me the color of it and if you can count the teeth.

chances are you need to drop 5 teeth to be on and i doubt they make it

Bubba 95SN

Might consider a swap of 7.5" to 8.8" differential.

91redbarchetta

Im running a T-5 and I can't remember the color the gear, its been a few years since swap, but will check it out!! thanks for the info!!!!

91redbarchetta

Yeah, the 8.8 from the donor has been collecting dust in my garage, and every spring i say im going to swap it out, but for some reason it never gets done????