The Stovebolt Site Forums The Shop Area General Truck Talk Rear end upgrade

Am very seriously considering upgrading the stock rear end in my '56 3100, to a 3.38 to 1 rear end. Of course the rear end gears and the installation kit is available (also understand I have to install a speedo adaptor), and everyone I have talked to says this is a fairly easy swap. Has anyone out there done this, and what is involved (special tools, etc.). What are the +'s and -'s for this upgrade (better fuel mileage, higher highway speed, etc.). Would appreciate hearing from those that have done this.

Brian, I am in the process of changing out the 3.90:1 gears to 3.38:1 gears in my truck. The problem with this upgrade is that the 3.38 gears are on a 4-6 week back order everywhere I have checked. A couple of the vendors said they think they will have them by the end of the month, but I will believe it when I see them. Apparently they have been out of stock for quite some time and some of the vendors are removing them from their catalogs. I would encourage you to inquire about these gears to every vendor you can think of, so they in turn will bug the supplier. Maybe they will make us some gears if we bug them enough. Anyway don't tear apart your rear-end until you know you will be able to get the gears like I did. :mad: Let me know if you have any luck locating these 3.38 gear sets. Thanks.

Jim

Jim- Bryan: I've got a 54 that needs a new chunk rebuild too. #338-1 would be just fine. Could you keep me in the loop so I can order one too? Many thanks in advance.

Dale

Hey guys---Based on Jim's response, I phoned Angie at Chevy Duty to find out if they are in stock or if an ordering problem exists. Will let you know when I hear back from her!

Ive had mine ordered & paid for for 2 months now. They keep saying they should be in any time. On that 54 the updated gears are 3:55. I believe they are readilly available.

I can't speak for Dale's 54, but 54's rear-end has been converted sometime along the way to a ~57 open drive line rear-end. I will let everyone here know when the 3.38 gear become available and if anyone finds them first I would appreciate hearing back as well. Thanks.

Jim

I removed the 3:90 56 rear end from my pickup and swapped in a 65 or 66 half ton rear with 3:08s, width was same. I did get some serious help from a buddy that ran a wrecking yard. Belive this next generation pickup could have many ratios, oh it's six lug as well.
Best of luck guys.

i bought a 71 c/20 camper special about 2 years ago wasnt first choice but the price was right for the condition and thought i could take my time and make it work for me. one of the first things i did was take out the three speed trans. and put in a 89 5 speed which is hydraulic and only a few minor adjustments had to be made. but i love it my problem is the rearend i want to stay with the 8 lug because my wife bought my rims, but it is really slowing me down and killing me with gas what other rearend can i put in there that will better suit the 5 speed tranny? and stay with 8 lug?

Shannman71, If I remember correctly the 71 C/20 camper special had 411:1 gear and the gas mileage really stinks, the early to mid 70's Burbs had a 373:1 option these are 8 lug and should improve your mileage. But at my age the memory is not what it use to be but someone will correct me if the old memory has failed me once again

Well everyone, I heard back from Angie at Chevy Duty, and in fact THEY are also out of stock on this rear end. She said it may be a month, maybe six until they come available. If anyone hears of this kit being available for the rear end swap, a lot of us here would appreciate hearing about it!