I have a '89 and it is the 4 speed auto with overdrive. I know the stock rear gears are not great for acceleration. I was thinking of going with 3.07 gears as I heard those are the best for the quarter mile on this car. Should I go with something different? Is there any kits where I can use the stock case and drop in a different ring and pinion? Will it be reliable? Thanks.

 

Upgrade to the Dana 44, the Dana 36 is weaker to begin with however neither is bulletproof.
Yes the 3.07 gears are great for performance but the auto trans has such a good first gear to launch with.
I still have the dana 36 with 3.07 gears and has lasted the last seven years with the car supercharged, the half shafts are the weak point they twist and break to save the dana 36.

60 mph @1900 rpm with the 3.07 diff with 275 40 17 tires, if it helps.

 

Thank you for the reply! I don't have the cash yet to comfortably buy a dana 44. Maybe in a few months. Ive read that 3.07 gears are not too hard on the dana 36. Where is a good place to buy the 3.07 rear gears that drop right in. Link?

 

Where are you located? I've a 3.07 with fresh bearings and seals in the "4-sale" section, it's complete with short axles. It would be a very straight forward install BUT the speedometer calibration needs to be accomplished also. I may have the required hardware for that also.

 

Where are you?I too have dana 36 with 307s .Its out of my 85.I installed 44 long time ago,back in 1999.I live in Canada.JOHN.

 

See the link below a great site for the speedo gears .

http://www.transmissionsone.com/speedometer_gear.htm

 

YOUR RIGHT ,its a good sight

 

when I used to spend alot of time on 3rd gen they had done alot of research on 3rd gen tpi equipped camaro's seems the tpi and 700r4 liked 3.43's.But vettes are different, lighter,widder tires,different front to rear wieght bias,rear ifs.Soooo, guys that have been here a while, what's the best gears for a stock auto tpi vette?

 

3.07's

Vic

 

I have a ring and pinion change project currently "in flight" on my 1992 (LT1) convertible with automaic transmission.

Mine came from the factory with the optional "performance ratio" (2.73) instead of the basic 2.59, but that is still way too numerically low.

I have vehicle performance modeling software that I fed my car's info into, and the software shows that a 3.54 ratio would be pretty ideal for my needs. I favor nimble performance at the expense of a slight drop in fuel mileage, and the software showed me that:

- The horsepower available in top gear (i.e. overdrive, without a downshift) at 60 mph increases by about 1/3

- Top speed is unaffected since the car is so overgeared by GM to get the last tiny increases in gas mileage

- 1st gear will still be good to 40 mph

- The zero to 60 time will drop by at least 4/10 of a second.

I found the best ring and opinion setup for ym needs: Richmond Gear pn 49-0143-1, which is Richmond's solution designed specifcally for Corvettes with the 2 series carrier inside the housing (like my current 2.73 ratio). It is a "thick" gear set, which means it is STRONG compared to the other inferior approach of spacers (which is unacceptable from my view). I bouhgt it from Summit (in STOCK there) for $336 or so, and also 2 quarts of the Mobil 1 75-90 LS lubricant (intended for limited slip differentials (about $10 per quart as I recall).

The best local hot rod shop has done a bunch of Corvettes, and says they will take care of the supplies and installation kit, and the speedo gears, and do the install.

My installation is scheduled for August 5th. I plan to post afterwards to let people know how well the change works and if I ran into any issues.

Jim G

 

cool

 

Question. If you think you are going to buy a D44 in a few months or even within a year, why bother with getting new gears for the old D36? All you are doing is throwing good money on a weak posi. I'm reasonably certain that gears are not a Bolt In operation in ANY sense of the word, having seen them done before. It takes time to get the footprint right. You might have to take it out a couple times to do so. Why not wait for a bit and then get a D44 and save yourself a few bucks?