4:11 rear gear swap

[Gary R.]

Re: 4:11 rear gear swap

My friend bought what I said was an internet vette because it had every upgrade and gimmick on it Most of which were not needed However there was a Gear Vendor OD in it. This barley fit in his 78 and the drive shaft was shorter than a 1/2 shaft It wasn't a good match and he removed it

[Gary S.]

Re: 4:11 rear gear swap

My 1972 LT-1 had 4.11s and a CR transmission , and like you, I wanted a better cruising gears. Two long trips from Pittsburgh to Atlanta and then Charlotte convinced me to swap. As others have said, it required slipping first gear each time and the low-speed performance wasn't good. Just last March, after almost 20 years, I swapped back to the 4.11s as I no longer do long trips with the car. I live in the Pittsburgh area and Bairs Corvettes in Linesville, PA did my work. I am very happy with the results. Now I have a great set of 3.36's sitting in my basement .

[Mark E.]

Re: 4:11 rear gear swap

Wally,
I'm not sure whether your car is a judged car or driver or both. That said, you could consider an overdrive transmission. Several manufacturers make them and I believe some will fit inside the transmission tunnel without modifying the tunnel. It would give you the best of both worlds. Low first gear to pull away from a stop without clutch slipping and reduced final drive ratio for better mileage. For example, if you have a 5 speed overdrive trans with a fifth gear ratio of 0.85:1, the final drive for your 4.11 rear will be reduced to 3.49 (0.85 x 4.11 = 3.49). Just a suggestion but this might be a better option than changing the gear or complete housing in your car.

Terry

I'd like to hear from someone who did this swap. I researched this a few years ago and was left with some questions. One supplier said the Tremec 5 speed barely fit without modifying the tunnel but after asking some questions learned they never checked with the battery cable installed. Some kits had a connection for back up lights, some did not. And no kits I saw had a provision for connecting the steering column lock cable. I wonder if these issues have been addressed. Of course some of these problems are unique to C3.

[Joseph L.]

Re: 4:11 rear gear swap

It is a smoother feel to have a close ratio transmission, but- An easier solution than changing the rear ratio is to change to a wide ratio transmission. It is a lot easier to change back with a 2nd transmission rather than a 2nd rear gear set.
A close ratio w/ 4.11 is the same overall first gear as a wide ratio w/ 3.55.
A wide ratio w/ 3.36 is the same overall first gear as a close ratio w/ 3.9.

[Wally A.]

Re: 4:11 rear gear swap

im on board and received plenty of input... hwy. 3:36 will keep the revs down about 1 thousand RPM, lot of good blog but tend
to agree with you. thanks Wally