Topic: rear differential swap
in Forum: C3 Driveline Components
Lifetime Memberfound me a store selling an eaton posi differential for 63/79 corvette...
applications: GM Corvette: 1963-1979; 10 bolt; 8.20 ring gear, 17 T spline axles, 4.11-4.56 gear ratio.
when I replace the tranny in the vette, I want to swap the rear differential for 4.11's...my question is can I take off the stock 3.08s and swap this unit onto the car, or would there be some reason it wouldn't fit (namely, I don't understand the numbers given for ring gears and spline axles and so don't know if I can just swap em out).
I'd appreciate some help.
Mike
My old Stingray...sure do miss it:
(click image to see a bigger version)
Lifetime MemberMike
My old Stingray...sure do miss it:
(click image to see a bigger version)
Lifetime Memberalright, so since that Eaton thing required me to buy additional parts...I'm looking at this.
A FACTORY ORIGINAL GM REBUILT 411 POSITRACTION REAR CENTER SECTION(COMPLETE) FROM A 69 VETTE.
Once again, I know nothing about differentials, and the seller hasn't gotten back to me yet...is this the entire unit or would I need to buy more parts?
http://www.C3VR.com/member_pages/6601_6700/6623/56613Dsc0155 5.jpg
http://www.C3VR.com/member_pages/6601_6700/6623/56613Dsc0155 8.jpg
http://www.C3VR.com/member_pages/6601_6700/6623/56613Dsc0155 9.jpg
Mike
My old Stingray...sure do miss it:
(click image to see a bigger version)
This is not correct. You can buy a thick 4:11 gear that will bolt up to your 3 series posi carrier. Your supplier should be able to get this gear for you. If he can't, call me up and I'll get one for you. 800-418-5397
Dan
Phil
Lifetime Member[QUOTE=custom76] FYI. Don't mean to scare you off but the 4:11 gears will make your highway experience a rather high and winny one. I just hope you don't mind the (greatly)inceased rpm's at highway speeds (from a 3:08). Great for boiling hides but a more street friendly ratio's would be 3:55-3:90. These still have a good amount of low end grunt and you will be happier with the gas mileage and drivetrain wear.
Phil[/QUOTE]
I'm not too concerned about the highway performance, and hopefully the rpm's won't jump up too high. the 4.11s are going to be used with a 700R4 overdrive transmission, so hopefully it shouldn't be too bad.
Mike
My old Stingray...sure do miss it:
(click image to see a bigger version)
Here are some gear ratios for different GM trans so you can see the difference in ratios.
Gears.............1st.......2nd....3rd....4th
Power Glide.......1.76......1.0
TH350 ............2.52.....1.52....1.0
TH400.............2.48.....1.48....1.0
700-R4/4L60.......3.06.....1.63....1.0.....70
200-R4............2.74.....1.57....1.0.....67
4L80E.............2.48.....1.48....1.0.....75
Note: Some Powerglides come with a 1.82 1st gear.
Also when installing a 700r4 be sure you have a good trans guy set up the TV cable to the engine. The trans can be damaged if the cable is not set right.
Phil
I'm a big fan of the 4:11's. Although it is a bad highway gear there is nothing better(to me) than getting on it and it going. And going quick. 4:11's shouldn't too bad w/the 700r4(RPM wise).