Gear Change

[khryslerkid]

Back in the early 60s I was driving my 60 Ply convert with a 361 4-barrel & Torqueflite. I had 14 inch wheels, relatively small tires by today’s standard. I replace the stock rear with 4.56. Then I changed to a 4.89. Objective is to hit top speed in the 1/4 mile traps. Yes, I drove it to school and to the strip. Gas was 25 cents per gal. No problem, or so I thought at the time.
Got to decide....do you want to win at the strip....or get good gas mileage?
In the late 60s I drove a street Hemi 4-sp with 4.10 gear.

Same here. Back in the mid seventies I had a '64 Polara 500, mild build 383 auto. Installed a Dana with 456 gears. Never even thought about it. Drove it to work everyday and to the drags on Saturday.

 

[BSB67]

Always depends on what you want. Considering you have 2.76 now, a 3.55 will be a big and noticeable change for you.

Your goals and expectations play the biggest role in what gear is right for you. But the engine and transmission also plays a role. For a 440 auto car, 3.23, 383 auto, 3.55 or 3.91, 340 4 speed, 3.91 or 4.10, presuming mostly around town driving.

 

[Derek L DiLaura]

I’m thinking of going with some 3.91s to improve acceleration on my 68 charger with 383/727. It currently has 2.76s. First, is it worth it and second, any idea on cost for a shop install?

I changed mine from a 323 to a 355. I was lucky as a found a rear end pig, 489 casing with the 355 sure grip locally cheap.
Before that, I checked and found a shop that would do it for $500.00. I checked ebay and they had a lot of them but they were out of site on pricing, 1k and up.

 

[Derek L DiLaura]

A local shop said they would do it for $500.00 which was fine with me. I got lucky and found one with a 355 sure grip for half that with the 489 casing with sure grip. It made swapping easy.
I also checked on ebay and the prices were all 1K and up.

 

[Chris Hanley]

I’m thinking of going with some 3.91s to improve acceleration on my 68 charger with 383/727. It currently has 2.76s. First, is it worth it and second, any idea on cost for a shop install?

I went from 273s to 391s. ( w/stock 14inch wheels and hubcaps) Woke it up but revved the hell out of it. (65MPH = 3500 approx RPM) Just installed 355s. have not driven the car yet, but I think it will work fine now.

 

[khryslerkid]

I'm using 3:23 behind my mild build 440 and it's a good all around gear. 3:55 would be better for hole shots but how often do you do that.