The Stovebolt Site Forums The Parking Lot Big Bolts updating the big bolt drivetrain

hey guys back so soon, Truck is a 1954 GMC 350 (2 Ton)
trying to brainstorm ways to up power production and be able to use public highways safely. so 2 things need to change. engine and transmission. id like to keep the original rear end (i dont even know what its called and cant find gear sets for it if someone could point out its designation and if there are gear sets for it i could keep the 4 speed as well and not need to lose my parking brake that would be awesome!!) if not i have a tremec 5 spd which could go behind my v8. some said the v8 swap is hard because of the steering box, that makes sense but is it terrible? i mean for the smaller trucks they can swap right over to a rack & pinion problem solved but us big bolts dont have that luxury that im aware of. so how bad is it? thanks for all your help.



(i feel like a zombie after scrolling through hundreds of pages of threads)

Please tell us what exact truck you are working on.

One option to keep your SM420 with park brake (and assuming working and fairly accurate speedo) is to use a ranger torque splitter (overdrive) that goes in front of the trans, between it and the bellhousing.(Advance adapters sells them new. ) That is what I have in my 58 t-ton. That said, it will do 70 on the freeway, no problem. (don't really want to go much faster than that).

Please tell us what year your big bolt is. The term “big bolt” is used here mainly for the 1.5 ton but also for the rare 2 tons. The 1.5 tons have the Eaton H110 rear axle and ten pugs on the rear 5 in the front. Nearly all of the 1.5 tons came with 6.17 gears, the only other option was a 5.43 ratio. I happened to find a set of 5.43s after searching eBay for months. There are some excellent gear ratio calculators on the site www.4lo.com I highly recommend.

Item #1- - - -you haven't mentioned anything about getting that heavy hunk of iron STOPPED once you gat it up to speeds it was never intended to run. The people who have to share the road with you and your unguided missile that won't stop or steer properly didn't sign on to be part of your dangerous joyride.

Item #2- - - - -punctuation and capital letters are your friend- - - -us old geezers get out of breath trying to read your run-on sentences.
Jerry

Good morning from already hot Central Florida. I have been looking at for two years and not really paying attention to a big ol 46 2 ton. My friend went over yesterday and got the radiator out of it (5 core), to use in the 34 p/u with 440 Super Wedge NASCAR engine. My question is, it has a 2 speed rear end, a motor that looks kinda like a 235, governor on carb and a strange looking rectangular coil. 4 speed granny and military green paint in places that aren't painted brown. I cannot talk to the guy that owns it because 17 years ago I had a serious discussion about him trying to date my daughter (persistently), he was bigger than me but, the bigger they are the harder they fall. Almost was arrested because under Florida law one is not supposed to keep kicking someone in the head everytime they move. Only because the Sheriff is my cousin and I was a DOD Marshall. Etc. Forgive the side story but it does involve a BIG Stovebolt. I will try to get pictures if the Guy that run's the salvage yard is out back, two friends are going to keep him busy. Don't feel like getting into a fight, can't fight that well anymore. What should I do regarding what to look at. If the old boy is prior military shouldn't the engine have a G.I. tag? Doc.

mine is a 1954 GMC 350 (2ton) i cant believe i forgot to add in my truck!!!

thank you! yes im looking for around 70 without screaming not that ill be going that fast but to have the option makes life 1000X easier.

1954 gmc 350 (2ton) 5/10 lug wheels, has the 2 speed rear end, ill have to count the bolts and get back to you in a little bit.

Jerry, i was told to keep posts short in my last one so thats what im doing. p30 spindles so i can use disk brakes w/ hydroboost for the front hoping to rebuild the rear brakes unless there is some form of update kit for the factory rear end. but i know nothing about them so i cant do much research when i dont know what im researching.


#2 grammer is not a strong suit for me, i think youll be fine reading run on sentences you dont have to breathe with your eyes so youll be alright.

i believe i did come across military engine ID in the hundreds of pages i was reading from the big bolt forums. but this isnt the spot. your question is hidden under a thread that has nothing to do with G.I. running gear. goodluck!! im still searching too so i know the feeling!

Ok and thanks, the salvage yard is open half a day today. I will get over there next week. Doc.

As far as your rear axle it could be a Bendix or a timken. On the timken the modle # will be on the top of the axle forward of the pumpkin on a flat spot. That #will give you the gear ratio's. Your truck wasn't made to go more than about 55 mph. The wheels and tires aren't balenced and will vibrate and that truck isn't going to stop very fast even unloaded. If you want more power get a 261 c.i. it will bolt right up to your bell housing and motor mounts. Adds about 10 h.p. in stock form. Add headers, dual carbs and a mild can and you will have all the power the truck needs. Remember, the gearing was very low in those big bolts for a reason, they were made to work, not Cruse the freeway.

Whatever the two speed axle is the ratios are probably slow and slower. So, one needs to get a Brownie or such, and then upgrade the brakes, or get a modern rear axle with modern brakes.

For bigger trucks, 630 etc., higher ratio two or single speed rears are available, I got a 4.13/5.59 for my original 6.5 axle, however, one needs to find someone(rare) who knows what one is talking about.

Ed

I feel the need to mention im working on a far better braking system for the truck as a whole. You are correct they aren't made to go fast but today's roads demand more from our vehicles overdrive and larger tires will work on getting it up to a safer speed on todays highways, balancing beads work wonders on updated rims and tires generally speaking they are so large that they usually don't get balanced at all.
This is the information i was looking for! so its either a bendix or timken any idea what the models were? thanks!