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2.29 to 2.73 worth the swap over?

2K views 5 replies 3 participants last post by  M&M CUSTOM 
#1 ·
my 82 grand prix currently has a 2.29 stock gear set, i recently bought a parts car and pulled the rear end off wich has 2.73 Gears (.44 higher)

would it be worth the swap? i know my highway rpm would go from like 1700 RPM to 2100 rpm with my TH350 and 295/50R15 tires. i cant imagine loosing much gas mileage on the highway i dont think.. but would i notice a differnce in performance?

other then the whole rear axle and brake swap. all i would need to change is the spedo gears in the tranny correct?

the cars just a daily summer driver with probaly 60+% city driving
 
#3 ·
Actually, given your TH-350 NOT having an overdrive, and your rear tire size of 295/50/15, this setup with the 2.73's will act like an overdrive.

My Malibu has a final drive ratio of 2.61 when the TH-700R4 shifts into fourth gear. I swapped my 2.29's for a set of 3.73 I got for free when my cousin parted out his S-10.

For your intended "just a daily summer driver with probaly 60+% city driving", you can get away with it, but it would fare better on the highway than what you have now.

Like Poncho said try for a little higher ratio, or you could use the 2.73's and drop a tire size or two to give the same effect.
 
#4 ·
Thanks for the replys

i think i might just swap in the 2.73 for this year or if i find some little taller ones like 3.08 or 3.23, then next year get a set of 3.73 and install my 200r4 thats sitting out i the shed.

i pulled the 200r4 out of my 86 cutlass parts car, guy said it was a rebuilt tranny and close to 20,000 KM (15,000miles??) never got to drive it because well the engine was knocking and didnt want to take the chance of that and no insuarnce.

after i got the trans all out and sitting on the floor i notice the rear end spline in the tail shaft housing was just laying down inside and wobbly, all my TH350s ive had were solid... is this somthing differnt with the 200r4 or is it messed up?

after i paid him and waiting for the tow truck to show up, he was talking and said he used to do burnouts and doughnuts all the time in the car(saying how much power it had before the nock), who knows maybe even some nuetral drops... :eek:
 
#6 ·
montea said:
oh and 2 last questions...

will the spedo gears from the 200r4 work in the TH350??

what is the single Green wire attached to the drivers side of the trans for?
The speedometer gears for the TH-2004R will not interchange with any other GM transmission.

The single wire on the drivers side?
The only GM transmission I know with a single wire on the drivers side is the TH-400, it is the "passing gear" activation power wire, the TH-400 "passing gear" is activated by applying 12 volts to a solenoid located inside the transmission through a bulkhead connector located about three quarters back on the drivers side of the 400.

If there is a four prong connector near that same location, the transmission is either a TH-350C (350 with lockup torque converter),the TH-2004R (which you can already identify as you have one there), or the TH-700R4 (which we are accurately guessing it is not).
 
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