Hey, does anyone know what gears came factory in '89 Formula 350s? When I first bought the car, everyone agreed that it had 3.42s, but after looking for PROMs in my T.P.I.S. magazine, they only have the '89 5.7L Formulas with 3.27s. Did they put Borg and Warner gears in the WS6s?? The RPO(?) codes have been peeled out of the glovebox, and I couldn't find it on my rear axle. Does anyone know? Also, the car still has the dual cats: are they completely worthless or does it increase the performance of the car? I drag on everything, and it's a huge pain having an exhaust with that low of a clearance. Would it hurt it to cut them off and rerun my exhaust with straight pipes and a namebrand muffler?

 

if your rearend is a 9 bolt then it is a borg-warner rearend, i belive i could be wrong if am please correct me, from what ive been told the 9 bolts were aussi rearend's or BW rearends, and they are stroger than stock 10 bolts but i dont belive 350 cars got 3.42 gears you probably have 3.27's but i will tell you a trick that worked for my rearend(s) and worked for my friend as well, but i was told and again this worked for me, that if you put your car in drive (3rd gear) then go an even 70mph whatever your taching on will is what gears you have for example with my 2.77 i was taching about 2700 rpms and with the 3.27's im taching about 3300 rpm's.....try it PS: i would keep the duel cat's

 

i believe my 1988 formula 350 had 3.27s 9 bolt bw and my 1991 formula 350 has 3.23s 10 bolt



the factory dual cat setup was good for 10 horsies!

 

I have 3.27's and I just got back and at 70 MPH I am at 2300 RPM 60 was 1950RPM and 80 was 2700 RPM

 

Mkos do you have a stock 700-r4 tranny? or what?, and if you have any mod's to you motor like a cam or somthing mite throw it off, it worked for me, it must be nice to be taching that low

 

MKOS1980, did u have your car in 4th gear? my car has a 3.23 10 bolt (confirmed by SPID codes), and i get 2000 rpm at 70mph in OD.

 

I have the origional 700 and I was in 4th. I also confermed the rpms with my Tech 1 and Diacom

 

2.77s tach at approx. 2000 in OD.

 

if you have dual cats you have 3.27s...my buddy has an 89 Formula 350 G92...and the dual cats are crap, worth nothing.

 

if you guys were in 4th or overdrive it wont work you have to put your car in drive "D" or "3rd gear and go 70 mph try that and see what your taching

-Don

 

ok heres a problem then, i have 2.77 gears according to the plate on the rear and it tachs at roughly 3300 in 3rd.

over 2000 at 65 (roughly) in overdrive, at 60 its almost exactly at 2000 in 4th.

thoughts? what should a stock 2.77 be running in overdrive at 60/70 mph. it seems my rear may not be what it says, maybe.