The Stovebolt Site Forums The Parking Lot Big Bolts '56 6409 1 1/2 ton highway drivability

First let me say, this site is great. I've been searching around for a couple of weeks now and, the knowledge here is amazing.

I am new to Stovebolt ownership. Actually I won't get her home for another week or so.
What I know so far: 1956 Chevrolet 6409, 2WD, 1.5ton, 4speed, 6 bolt Budd wheels, 16,000GVW, 6cyl.

I am really excited to get started. The truck has been "parked" for at least 30 years. It has been in the family since it was discharged from the Army.

First major item on the list is getting her highway capable. I won't be on the highway a lot but, materials and supplies
are 60 miles away down I-25, with a 75 MPH limit. I have read several threads on axle swaps for the AD's and, possible donor vehicles for the swap.
I wouldn't mind doing the swap however, if I could find compatible gears for the diff I'm sure I could save a bit of money (really needed for other parts).
The axle swap might be near impossible for me, no salvage yards nearby.

So, if I could pick the community brain. Who has had good highway results with a gear or axle swap? Were the pieces relatively easy to get?
If you had it to do over would you do anything different?

Thank you in advance for any advice.

welcome to the site! If your truck is a 6400 series, it should have a 2 speed rear end, does it? 6400 series is a 2-ton. If you have 22.5 wheels on it (tubeless tires) you should be able to get 9R22.5 tires (at least on the rear, might need a bit shorter on the front for turning clearance).

My 58 2-ton will go 70mph @ 4200 RPM. 3600RPM is 60 mph just so you get an idea. (I have 9R-22.5 tires all the way around).

RmJr, Welcome to the site. Lots of knowledge here.

I don't currently have a running big bolt, but for years I had a 46 2-ton. It was a stock truck with 8.25 rear tires. Single speed rear end. It ran the original 235 splash lubricated babbit rod bearings. I freshened up the engine, but all stock. I was even running points ignition and the original radiator. The only non original things were a 12 volt electrical system and disc front brakes. The truck now resides in Arizona and I'm sure the owner would give you a ride if you are close to him.

I was able to run on the highway comfortably at 55. I would occasionally see 60 and at one time I looked down and I was doing 68. It most liked the 50-55 range. Loaded was another story. The most I had on the back at one time was 12,000. It went, but not very fast.

Get it running on all the stock stuff. Make sure the brakes work well. Then go drive it and judge for yourself if it will work the way it is. I suspect it will as any modifications to make it go faster will likely become very expensive by the time you are done.

Good luck and keep us posted on your progress.

Just to make sure we are all on the same page, nomenclature wise, your truck is not an AD. You may already know this but your post says you’ve been reading on the AD’s. Your truck is the next generation called the Task Force era. Later model truck rear ends can be swapped in but require some fabrication skills and a welder. Search the site some more and see what further information you can find.

I echo Randy's comments...get it running and stopping and see if it's the truck for you. These trucks were not designed to go as fast as we go now days.

What kind of loads will you be hauling?

As for different gears, there are none. If you want a faster gear ratio you'll have to do a axle swap to something newer.

IF you're lucky you 'll have the 22.5" tubeless wheels, if not you'll have the 20" tube type widow makers.

The standard engine was the 235, the optional engine was the 261.

The 4-speed will be the SM-420 (granny gear 4-speed).

The rear will be the 13,000 pound 6.17:1 single speed as standard issue or the optional 15,000 pound 6.17:1 or 7.20:1 single speeds, or the 15,000 pound 5.83/7.98:1 or 6.40/8.72:1 2-speeds. Hope you have the 5.83 2-speed, but with the 16,000 GVW I'm betting you have the 13,000 pound standard issue single speed rear...the Army liked to keep things simple.

Mike B

both of my 6400 trucks are 16,000 GVW and have the 2-speed rear but, yours may not.

WOW! best response time ever! Thank you.

I believe the tire markings were 20 x ?8.25? up front. I can't remember the rear.

She is tagged as a 1 1/2 ton, 4x2. I was hoping to find a 2 speed diff but, no luck.

Honestly I'm not 100% sure it will even roll. I have prepped and started her but, only in neutral.

I agree, check the brakes, drive it.
I know that modern brake linings can sit for quite a while before (if ever) needing replacement. I understand that our brakes have to be relined,correct?
So that might take me some time to find someone, good, that can do it.

Around town, for work, I might actually load her up to capacity. I'd like to show up on site with 9000+ on the bed.

Not close to AZ, sort of. I'm in the NM Rockies. Obviously I won't be loading her down to often.

This will be the oldest truck I have worked on. I am extremely excited and, a bit worried. whatever happens it'll be fun.

If it's been parked for 30 years the chances are it has 20" wheels.
But I would agree to get it running first and drive it some, rather than just assume it won't be fast enough. It may surprise you.

1956 was the first year for the 22.5 wheels on Chevy trucks.. A lot of people did not trust the tubeless tires as much as the tried and true tube type so, there were still a lot with the 20" tube tires sold as well. My 58 had 22.5 tubeless on it, except for one rear wheel, they had swapped both on that side for 20" (widow-makers). They probably needed new tires and had those sitting in the shop or on another truck that was not in use.

Ok, new problem. (old problem I thought I'd leave for down the road)

I have looked into the tire situation. I have found one shop that is willing to work on 2 piece wheels. I am not sure if they're in great shape or not but, they hold air, at
least the tubes do. The rubber is another story, dry rot everywhere. I know that I need 8 new tires.

Could anyone suggest a good place to start looking? Is there an aftermarket
for replacement wheels?

Another question for you guys. I am wondering about the sizing for the tires?

20x9 cant be all the info. What were the tire diameters GM used?

Thanks again for all of your shared wisdom.

8x20 or 9x20 is all there is to the old tire sizes. 9x20 is 9" wide and a 20" rim. I would look in wrecking yards for 6 hole Budd tubeless wheels. They are out there, used on a number of trucks. (not just Chevy). You can find them on moving trucks, some busses, etc. I would NOT use the Firestone RH-5 wheels if that is what you have. They are called Widow-makers for a reason and were sketchy 30-40 years ago! I don't think it is even legal for a shop to work on those anymore.
here is a link to tire sizes and inflation (1956 shop manual supplement) http://chevy.oldcarmanualproject.com/shop/1956sctsm/56sctsm1006.html

You are looking for 22.5" x 6.75" wide 6-lug tubeless Budd Wheels. As Mike said they are out there and not that hard to find.

The tubeless tires are always one size larger numerically then the matching 20" tires, so a 8.25 x 20 will be the same width and diameter as a 9.00 x 22.5 tire and a 9.00 x 20 matches up to a 10.00 x 22.5.

The Firestone RH-5's were discontinued decades ago due to them being unsafe and having the capacity to explode apart without warning. They can be ID'ed by the 2" locking band running around the center of the rim, there is no lock ring at the tire bead. If this is what you have DO NOT AIR THEM UP IF THEY ARE FLAT as they force they generate when they blow apart can lift a car off the ground...your head and arm don't stand a chance!

Mike B

Thanks guys,
The wheels on the truck are 6 lug. They have a strange split ring on the face of them.
Still not sure which ones they are.

I can't seem to post a picture of them from my phone.

I was wrong, nothing new there. The truck doesn't have the rings on the wheels, the trailer does.
I'll post pictures of them. If you guy's can tell if they are "safe" please let me know.

I am getting very excited, hopefully this weekend I'll get her home

The ones you want to avoid are the Type RH-5's

https://www.stovebolt.com/techtips/wheels/images/49_budd_catalog.jpg

It is easy to confuse them at a glance. I like the three piece wheels like the Type AR. I have had a Type RH come apart on me when I hit a pothole. It was on the front axle too, but luckily wasn't going that fast.

Your right rear outer wheel is an RH-5. Use that to compare the rest. It's hard to tell what the front wheels are from a picture because the split faces inward.

Mike B

Thank you Mike B,

Mike B
So if I understand correctly, I should be able to match the look of the wheel joint (circled) with the remaining 5 and tell if all my wheels are the
Widow Maker's? Did you by any chance see the picture i posted earlier, of the trailer tire? That seems to be a lot different.

P.S. I am really impressed with your trucks. The NAPCO is beautiful.

Your trailer has a 2-piece split ring wheel and they are still serviceable at any truck or ag tire store.

Yes, that raised center bead is the dead give away that the wheels are RH-5's, that's the only wheelmade like that and it's no longer serviceable.

Thanks for the compliment on my trucks...the NAPCO was sold about a year ago to the Museum of Off Road Adventure in Detroit Michigan.

Mike B

Thank you so much Mike B.

Congratulations on your "Museum" piece.