The Stovebolt Site Forums The Shop Area Driveline too slow

I have a 1956 1/2 ton 6 cyl three on the tree.Besides maybe putting in a v8 and auto what would I change the rear end gears to?

I'm guessing your running a 3.90 rear end.

3.38 3.73 could depend on the tranny too. May as well go 700R4 and have overdrive. There's lots of things you can do to the 6 cylinder too.

...I'm sure you'll get plenty of opinions on this!

I kept the 3.90 gears in my suburban and installed a SM319 3 speed overdrive. I easily run 70-75 with it powered by a stock 248. I have power front discs also, which I would recommend.

As Cletis wisely mentioned, good brakes are important. Also, I think it would be a good idea to pay attention to steering and all your steering/suspension components. Good luck!
Jon

If I put in a 4 speed manual trans what rear end gears do I need?

These guys know a lot more than I do, but here's my experience. I have a '59 235 that came with a 4-speed and 3:90 rear end. I found that I was in 4th gear at 25 MPH around town.

I got a set of 3:38 rear end gears from Patrick's in Arizona, and had a local gear shop (Pete's in Hayward) install them. What a difference! The truck is much more fun to drive, especially around town. I don't like to go on the freeway, but I can now. I live off a country road (yes, surprising in the SF Bay Area) and can still climb the grades with no problem. If I go to the City and have to start on a hill (and man, there are hills in San Francisco), I use first with no problems. Otherwise, I start in second.

The 3:38 with 4-speed sure works well for me.

Bob

There are numerous options depending on what you have to start with. Since you have a standard 3 speed, the only drop in replacement is the SM319 3 speed OD trans. You don't have to change the driveshaft, rear end or anything else.
If your truck came with a 4 speed, a differential gear change could possibly be the best solution. The T-5 OD trans is also a good option but will require some mods also. It has to do with cost, skill level, availability of parts, and what you plan on using the vehicle for.
Fred

Where do I get a sm319 od transmission?

First thing is put and ad in the Parts Wanted Forum. Lots of guys here make different modifications, for many different reasons. and offer up their treasures to others. Try it. I'll bet you find one.

What vehicle were they found in? There is a junk yard close to me that might have one. They have a lot old cars.

Look in GM cars & trucks 1953-69 for the SM319 (muncie 319)

I have a '50 with a '53 full pressure Blue Flame 235. It came with a 3.08 rear end and a Saginaw 3 on the tree.
It was great on the highway, but horrible in first (couldn't get out of its own way).
I switched to a T-5 from a mid 80s S-10 which had a 4 cylinder.
I also added a 4.64:1 limited slip rear end out of a 2001 Nissan Xterra. (A very simple swap, BTW.)
I now have an unbelievable truck to do whatever I need it to do!
I can climb up a wall, or cruise comfortably at 65 MPH. Shifts are as smooth as butter, and you will find that with the extra 2 gears, you will constantly be in the optimal power band of the 235.
You likely have 3.90 rear end gears. The T-5 which I mentioned above would be a perfect option for you. There is an adapter plate available which makes this swap easy.
Search this site for "Lugnutz T-5 swap". Lots of good info on his website.
Carl

I see many parts vendors referring to the Muncie 319 (over-drive transmission) being available from 1953-59 in cars and from 1954-59 in trucks.

Was that a factory option, available for 1953 and later cars, and 1954 and later trucks (that did not have an inclosed drive-shaft)?

The SM319 (4 bolt side cover) overdrive transmission is generally found in 55 through 65 cars and trucks. The later full syncro Saganaw (7 bolt side cover) version was available from 66 through late 69. It is not an SM319, however.
Someone may correct me but I think it is referred to as a SM323.
55 1st series trucks had an open driveline which would have made it available with an OD. I have never seen a (stock) pre 55 car with anything but a torque tube. Of course many have been converted over the years.
Fred