The Stovebolt Site Forums The Parking Lot Big Bolts 46 1 1/2 ton upgrade to modern running gear

Newbie to this and need help as to what to use. I have a 46 1 1/2 that I would like to use every day it will carry tools a welding machine etc. I would like to go with a 350/with an auto disc. brakes should I use the original frame and newer one ton rear end modern front end or is it better to use a whole new frame/running gear

If the truck is all original, complete, and appearance will not require much to get it looking good I would leave this survivor original. Those kinds of trucks are getting harder to find.

If you want more modern performance and classic look I think it would be easier to get a 1960 - 69 truck. You will still have drum brakes though it should have a split master cylinder and self adjusting brakes. Then engine and drive train will do highway speeds all day.

Less modification needed. Easier to drop in bigger engines and match up to better transmissions.

I agree with leaving it stock if what you want is a classic original truck. But, I would do the same thing if I wanted to drive it all the time.

Think about it, this truck was built to toodle down country roads at 40mph, not compete with traffic on a freeway.

I'm in the same boat, I have 52 2-ton GMC dump truck. I got it running and stopping with the stock stuff, and it's down right scary going down hills and very slow coming back up. I'm looking at SBC swap and more modern axles, even if I have have to go a little wider to do it. Also to get rid of the wheels the tire shops here won't touch. I am reusing the original frame as its robust and already under the truck. swapping in rears is easy.

I say, let the museums have museum pieces, and make the drivers safe and pleasant to drive.

I used to have a 70 fastback mustang that was a beautiful car, and terrifying to drive fast, or panic stop.

Daily driver it will be and with a load. I agree a newer truck would be easier but I have a 46 and I love the look of the 46 so now back to my question. I have been looking and it seems that a front end from a late 80's 1 ton is the best way to go. Are they cutting them in the middle, narrowing them and then mounting to the original frame?

I have a 46 2-ton that I have been using for my business for about 3 years. It started with a Craigslist search for a zero turn mower and this popped up. It didn't take me long to make a new gas tank, make a wiring harness, etc. but the thing that took time was the brake system. Once I made the disk brakes for the front I was using it weekly if not daily. I finally pulled the engine out 2 winter's to rebuild and this past winter I pulled the can off to repaint...

This truck gets used daily be either me or an employee. It gets driven on the interstate at 55 MPH, sometime has many, many thousands of pounds on the back ( the heaviest to date is 11,000. ) The only thing that is not original are the front brake components. Still has the babbited rod bearings and non synchro trans.

I say all that because the original trucks are not that bad to drive. If you want to do some upgrades I would pull the engine find a new crank and rods so you can get those pressurized ( takes on small modification to the block ), Go with a SM420 transmission, and get some better brakes. You won't run 100 on the interstate, but you will have much less time and money into your truck than if you reframe it.... You should read the first two articles in the Big Bolts area. Grigg has done a great job in describing how you would get a wider axle under these Art Deco trucks.

I will also suggest that you to find someone with an original truck to drive before you decide to swap everything out. You welcome to come up and drive mine if you can't find one closer.

$.02 worth from someone that daily drives a 46 2-ton.

I used a straight axle P3500 HD for my '37 GMC. Front axle and rear axle with disc brakes, hydroboost, Saginaw power steering. I was able to space out the front fenders to fit the axle width, which you cannot do.

Grigg wrote several good articles about installing modern disc brake spindles on an AD axle.

Saginaw steering boxes come in cross and fore and aft movement of the Pittman arm, same box, just different mounting, Pittman arms. GM 4wd and 2wd have the two.

D 70 and 80 rear axles come on these vehicles, so lots of options there.

The truck had 19.5 wheels and tires(10 on 7.25" bolt pattern) which, while the are great tires, they look undernourished on an AD truck. Early 22.5" wheels with this bolt pattern are great but rare. No-one makes modern 22.5 wheels with his bolt pattern.

Hydroboost and power steering work great.

Good luck.

There used to be a guy on here that widened out the front fenders on his Art Deco truck. Looked like it came from the factory that way. I think his handle was "Sublime", or something like that. Maybe do a search and see if any of his info is still here someplace.

GM did make full width AD fenders, hard to find though. I found a pair on a school bus, heard of another pair in KS, so, they are out there.

Thanks for the info and suggestions. That's what makes this web site so great. Don't know which way Ill go yet, I still have a lot of work to do before I get down to the frame. Its a MS truck that has been outside for the last 30 yrs. so right now I'm trying to get the sheet metal bead blasted and primed to stop the rust.

Check out Randy Domeck's disk brake kit for the front end. It can be easily adapted to any 1.5 ton ( as on mine) and is very well made. His '46 truck is a company workhorse that carries big loads and will stop on a dime.

As for gearing, I went with a '98 Chevy 3500HD dually rear axle. Fits great, you just have to move the spring mounts outboard a bit. Lot's of gearing options for highway speed.

I know there are a lot of folks here who insist on "keeping it original"...but I wanted a classic that I could actually drive. That means updating the driveline, gearing & brakes to make it safe. To each his own I say.

Oh yeah...and the engine is a rebuilt Cummins 4BTAA hooked up to an Allison 6 speed. Hardly original...but workable.

Ok I have a direction now I just scored an 1986 motor home on a p30 chas. for a $100. Motor trans. and a/c units are gone. My question is on the swapping of running gear on the front when I narrow the cross member to fit my frame (46 frame tapers in the front) do I narrow the new one to fit the frame or cut it straight and shim in the front as needed? My thoughts are to fit the taper and just align the wheels. The independent suspension should still work although they are angling forward a little. I know its been done so Im open to any help and knowledge

45/70
See my other post on this.
The GM engineers designed the geometry correctly on that crossmember front end. If you angle the A-arms forward, you are changing this geometry. In my opinion,a bad idea since they are much more knowledgeable than we are.

Another opinion:
This P30 front end drives very well,has serious brakes and rides pretty well.
But considering the work involved, I would probably take others suggestions here and add disc brakes to the original axle.
Maybe a modern steering box to tighten up the steering.

My truck goes down the road nice and straight at 70MPH and I don't think I could have done that with the original steering.
Others here have more experience with this.