The Stovebolt Site Forums The Shop Area Engine Shop Leaf Spring Perches on a 1955 1st Series Rear End

I want to put a 1955 open drive rear end in my 1954 1/2 ton pick up so I can have 390 gears and a 1955 overdrive 3 speed trans. I think the 1955 1st series had the spring perches on the bottom of the housing and the 1955 2nd series had the perches on top of the housing. The 1st series would allow me to install the rear end without changing the perches? Can anyone confirm the differences between the 1st and 2nd series rear ends?
Thanks. Rod

The '55 first mounts just as you suspect. If you can find one, try to get the springs too. They will have the locator bolt in the right place. Your '54 locator bolt is too far forward. I have read that you can drill a new hole in your '54 springs but I don't want to try to drill a large hole through 18 springs.

Thank you. I will try to get the springs.

Rod,
Just an FYI, your 54 rear end has 3.90 gears in it, so what you would be gaining with the swap is the overdrive only.
Samantha

He needs the open driveline to use the OD tranny. I'm gathering parts to make the same swap in my '54 GMC Suburban. I'm getting frustrated though. I've torn down 3 rearends and none are usable.

The 3.90 gears will be perfect for this tranny. It will be 2.73 in OD.

Hopefully someone can add a little meat to this.... My thought is that this is the perfect serenio where one would just swap out the pumpkin from a 55.2 to ??? truck rearend?

Good Luck

Samantha,

Yes, the 390 ratio may be the same but I really want the overdrive trans. My experience with several AD pick ups has convinced me the GM engineers really knew what they were doing when they matched the 390 rear end with the 1955 (and later)overdrive transmission. The combination gives you low rpm at highway speed and low enough gearing to pull from a dead stop. I have had 373's in a 1965 rear end combined with an overdrive trans and the 373's are just a little to high to pull a trailer up a hill or for a snappy start from a stop light (with a stock 235). We bought a 1950 Crown 14' travel trailer so I am getting picky about having both the low end pulling power and the low rpm's on these California freeways. In addition to all of that, the Chevy 3 speed OD trany has a lot of fun driving features, including free wheeling and shifting without the clutch at low speeds and gas peddle kick down shifting at higher speeds. I highly recommend it to any fellow bolters who drive much on highways.

Thanks. Rod

Cletis,

We are on the same page about the 390's and the 3 speed OD trans. Sorry to hear you are having to go through so many rear ends. I had a local wrecking yard guy, who does some repair work, install a Patrick's ring and pinion (333's?) in my 1954 Chevy 1/2 ton hydramatic pick up which requires a carrier from a 1953 or earlier rear end to work in a 54 rear end. He was bummed out when he went through five of his rear ends to get a good carrier for my rear end.

Thanks. Rod

I've read of it being done but I don't see anything perfect about it. It involves welding cast iron to steel. Not on my truck.

Patrick's conversion for 1/2 ton A-D rear-ends is 3.55. I found a few good 53 or earlier carriers fairly easily (one NOS carrier on eBay last year for $20 plus shipping, $10).

Tim,

Thanks for reminding me that Patrick's conversion ratio is 3.55.

Rod