The Stovebolt Site Forums The Shop Area Engine Shop 54 GMC running gear and engine

3 years after finding my '54 on a farm in Oregon, I am getting serious about going to work on it. I would like this to be more of an every day driver, but the gearing is so low (4-speed manual) and rear end gears that it maxes out at about 55 mph and it screaming pretty good. I am wondering the cheapest and best way to change it up. I do not know the gearing ratio. Also, probably will be rebuilding it. I dream of someday putting a little V8 in it with an auto tranny, but for now will redo the 235 (runs ok, but I know the 6th cylinder has low pressure. This is my first posting, and I am a 50 year old high school teacher (and baseball coach) looking to return to those days at age 17 when I took apart a few motors.

Hey Baseball welcome to the Stovebolt! More Washingtonians seems like a good thing to me!

Are you sure your GMC has a 235 in it? If its a US made truck I think it should be a GMC 248 if the motor is orginal. Mine says GMC on the value cover and the first three digits of the engine serial number are the motor size.

My '55 1st GMC (almost identical to a '54) will run 70+ easily with 3.08 gears in the rear, and the original SM420 4-speed. I used a '73 Chevelle wagon rear.

There are ring and pinion replacements available that go as far as 3.55 from Patricks.

gmcbaseball,
let me tell you, the old ways of messing with engines comes right back in an instant! Thirty five years means nothing as far as that goes.

Is your truck a 1/2 Ton or is it a heavier model. That will affect your gearing options.

My truck is a 1/2 ton, and the valve cover says Chevrolet on it, so sounds like the original 248 was replaced. The serial number has no numbers that indicated the engine size.
Too bad I guess. It is definitely powerful, just really low geared.
This things has been more reliable than my 92 Acura Legend, has never failed to start in 3 years. Hate to start tearing it apart.

gmcbaseball, I also have a 54 GMC 1/2-ton with a longbed that I am restoring. My original 248 had been removed before I bought it and a 261 Chevy engine was in its place. It is much cheaper to rebuild the chevy engines than the GMC engines by the way. If you have any questions about your 54 feel free to ask me as I am into the restoration of mine as well. You can see some pics of my project at:

http://community.webshots.com/photo/109000222/109003956oizrXs

So, has anybody out there used that 3.55 ring & pinion gears that Patricks, and Chevy Duty sell? Getting ready to do the same thing to my '53 Chevy 1/2 ton, with 4 speed & 235.

Also, any advice about upping the carb/manifold set up? Thinking of going with a Clifford manifold and ~350 Holley 2bbl. Any thought?

Thanks.

"I am wondering the cheapest and best way to change it up."

I'm reminded of the sign in Ye Olde Meck-a-nik Shoppe, thats say's- " We do 3 kinds of work here, Fast, Cheap and Good. You may pick 2 of these.
Fast and cheap, it won't be good.
Good and fast, it won't be cheap.
Cheap and good, it won't be fast.

stovebolts forever, enjoy them while we can