I have a 39 jc pickup, all orginal except the engine is a 235 out of 58 chevy. It has 4.22 ring and pinion set up. I'm looking to get another 10 MPH by putting taller gears in it. My question is this: Can I put taller gears in it without changing the entire rearend and touqe tube set up. And if so does anyone know how and where to find them (taller gears)?
39 CHEVY JC PICKUP RING AND PINION QUESTION Every time I see the initials J.C. I think about that man child born to a single mother that grew up to save entire the world. Thank you, John Conner! Consider that a bump back to the top and I hope someone else has the answers you are searching for.
If I recall a company called Patricks had some higher gears for at least back to '47, may need to swap in a 47-54 axle, but I think they had 3.55's. They may have some for older, I don't know.
Did the cars and 1/2 ton pickups use the same rear axle? If so, there was a higher ratio available in the cars. Something to consider.
Trying to find that info, I may need to reach out to the 39 master deluxe owners, thanks for the reply!
From what I have learned the pickup and p***enger car rear ends of that vintage are completely different as in nothing interchanges. The "tri-five" pickup rear ends will be close to the same gear ratios you have, the p***enger cars tend to be higher geared but you would have to redrill the hubs for six lug wheels.
Also, post your question over on the Vintage Chevrolet Club site: Vintage Chevrolet Club - Discussion Forum - Forums powered by UBB.threads (vccachat.org) Lots of info. about what you are looking for. Gene over there is very knowledgeable. P***enger cars with the automatic came with 3:55 gears.
That took some homework, JC = 1/2 ton light delivery pickup in 39 Chebby parlance. pages (gm.com) According to the pfd it has a 4.11 but There was an optional 3.818 available. Searching shows that most likely you are stuck with the 4.11 unless you make major changes as I am not finding a 3.55 gear set for that rear. The vendors show a 3.55 ring and pinion for 40 through 54 rears though. a 40/47 first series axle might swap letting you change gears but unless you get with pre 47.2 truck brigade that may or may not work. There is a pre 47 group on the Chevy truck board I hang out on but they aren't very active. The pre 1947 Chevrolet & GMC Truck Message Board - The 1947 - Present Chevrolet & GMC Truck Message Board Network (67-72chevytrucks.com) The problem with swapping rears from a 48 to 54 is that 48 an up use a Muncie transmission rather than the older small bolt pattern trans and I don't know if the torque tube is the right length or will even hook up. Swapping transmission to a later closed drive or to a 55/59 open drive calls for changing bellhousings to work with the later pattern trans.
Have you checked with Chevs of the 40's 800 999 2438 in Washington or Jim Carter 800 862 1913 in Missouri? They both support the old chevys pickups. Good folks Ed
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