PT81PlymouthPickup

Update on my rear wheel widening project in case anyone's interested? I couldn't find any 16" rims that had the offset I wanted, so after a bunch of measuring, I had the "Wheelsmith" make me two 16 X 7" vintage style rims with 3.5 backspacing. After painting, I mounted a set of Michelin 245/75R16 which have a slightly larger diameter (less than one inch) than the original 650-16 and much wider. The new wheels will accept the original trim rings and an aftermarket hub cap which looks very much like our originals, only without the logo. In the photos you can see some before and after shots. I'm sure some might think it a wasted effort, but I think it gives the 39-47 trucks a more robust stance by filling in those huge wheel-wells. It will be a little while until I drive it again. I'm hoping my slight increase in rear tire diameter doesn't affect performance too much? I'm pleased with the way it looks.

Also, I'm not sure what the original die cast screw thread was? Some of these things used speed nuts over a die cast stud. If you go the drill and tap method you may want to select a bit smaller diameter screw thread. Likely a 6-32 or a 4-40 ? You need to measure the dia. of the original studs to get an idea of which thread to go with.

Being a machinist and having access to a milling machine, I would carefully drill and tap the holes. Being the parts are thin, you'll want to drill as deep as possible without breaking through, leaving only about 1/32 (.031"). Be very careful tapping. If you apply too much pressure when the tap bottoms it could deform or break through to the outside surface. With a thin part like this, you'll want to use a bottom tap which will allow the screw threads to engage deeper. I would then install allen head stainless steel set screws. You can purchase them in various lengths. On final assembly clean and put a few drops of Loctite threadlocker. Be careful to not over-tighten the set screws or the nuts when you install. Should be better than new.

My 1939 1/2 ton has only the valve on top of the water pump to flow coolant to the heater core and a fan switch mounted to bottom of the dashboard. The defroster is actuated by a lever on the plenum attached to the heater. No knobs there, you have to reach under the dash and pull a lever to divert the air to the windshield. I'm pretty sure heaters were an option in those days? Mine says only "Deluxe" on it. I think it's an aftermarket and not Mopar? It works well.

Nice truck. Some would pay many thousands to create that patina.

If your going to swap engines, might as well go for a hemi. Of course you could go small block chevy. You already have the valve covers. Frank Elder might give you some grief though. Lols!

This thread on safety reminds me of an experience. When I was a teenager (a long time ago) I was at my buddy's house watching his dad paint a car outside in the yard. Using lacquer paint and propelling it with a propane gas cylinder because his air compressor was not working. He was doing this all the while puffing on cigarettes. Even as a dumb teenager, I thought this can't be a good place to be and high tailed out of there. The paint job was completed without incident? Lols! There's probably not one of us on here that hasn't done some stupid and risky things and most of the time got away with it. I'm amazed I survived my youth.

You can look all you want. Not sure how helpful I'll be? It's been about 25 years since I assembled mine. It's up on jack stands right now. I'm changing up some wheels and tires.

Looking good! Brings back memories of my build. Was fun some of the time, but took too long. Lols!

Damn the Chinese! Set that model on fire. ?

Yes, our trucks originally had a residual check valve built into the master cylinder for drum brakes. If you're keeping the oem style master cylinder the check valve should be removed if converting to disc. I believe the check valve would hold around 10-12 psi on the system which will cause discs to drag. I have a 2 lb residual for the front disc and a 10 lb for the rear drum on my system. This keeps a minimum pressure which relates to a faster responding pedal. It's more important on vehicles (like mine) that the master cylinder is below floor or below the calipers or drum brake pistons. I also added an adjustable proportioning valve to set the bias on my custom brake system. There are a lot of factors / variables when altering brake components that can possibly lead to an unsafe system. These are often unnoticeable until a panic stop situation. Automotive engineers calculate and test systems for production applications. I would recommend testing thoroughly in a empty parking lot somewhere before being too confident on the open road. I have learned the hard way. ? Also make sure there is some free play between the master cylinder piston and the pedal push-rod and if you convert to a split system master cylinder it's important you have full travel of the master cylinder piston in order to gain the safety benefit.

Jim, Last year I compared available kits for front disc brake conversion on my 1939 Plymouth pickup. The Rusty Hope kit is popular and I believe a good kit, but after careful comparison I chose Scarebird's kit because it did not require any modification to existing steering components. The Rusty Hope requires drilling out and tapping your steering arms and I believe another modification for the spindle nut cotter pin. It also will offset the wheels outward further than the Scarebird kit. I did not wish to modify the steering arms, just in case I ever decided to reinstall the drum brakes. Scarebird uses an aluminum hub, Ford Probe rotors, and GM calipers. I've only driven it a few times since install, but it seems to work fine so far. I've read others have had good results. The only minor complaint I had was the bearing dust caps did not fit properly. I had to tweak them to stay in. I too installed a Jeep rear and dual master cylinder, but I have drum brakes on the rear axle.

I recently had a couple of wheels made by "The Wheelsmith" from Corona, California. They seem knowledgeable and did a nice job.

Welcome Bill, your truck is looking sweet! I live just around the corner in Yardley. I Painted my 39 Plymouth with 1992 Ford Candy apple red. Looks almost identical to your color.

Obsessive compulsiveness is a good thing! ?

Yes, there are a lot of old cars and some not so old that have been worked on by un-knowledgeable mechanics, which could make them unsafe. Brake shoes will wear in eventually, but that could take several thousand miles. Vehicles with front drum brakes can be especially unsafe if not assembled / arced properly causing them to grab and could pull the vehicle to one side in a panic stop. Rear drum not done properly can cause safety concerns as well, but I believe not quite as critical as the front. We sometimes forget that automotive brake systems were / are highly engineered. Anytime we change things like replacing shoes with wrong radius, replacing drum brakes with discs, different sized wheels and tires, different sized master or wheel cylinders, different lining materials, adding proportioning valves, etc. etc. will deviate from original designs. If one is not careful, it could easily make a vehicle unsafe. Often I have read of repairs and modifications that anecdotally are reported as working perfectly, but in a panic stopping situation it may cost you your life. Sorry to be a drag!

Besides the proper fitting, the material has a definite effect. Even in the old days when linings were full of asbestos, they were not all the same. At my Dad's shop, we used to stock Bendix and Pennsylvania brands. The Pennsylvania linings were softer and rarely squealed, but did not last as long. The Bendix would often squeal but wore like iron. I can't remember now which one, but I remember my dad saying one seemed to stop the vehicles more quickly. I would think the softer material? You could also get riveted or glued. Not having all that much faith in adhesives, I choose the riveted when there is a choice. Now days, the reproduction stuff we buy for our vintage vehicles is a real crap shoot if it's a quality product. Even the old American brand name stuff is coming from China. Be careful!

Yep! I've had my share of mice problems too. Them little buggers are hard workers and have done lots of damage when I let my guard down. I don't like killing them, but when they mess with my truck it's time to go hunting. Lols! Living near the Delaware river, other critters have given me considerable grief too. Took the truck out for a spin first time last year and every time I stepped on the gas pedal it would almost die. After several hours of trying to figure it out, I determined a spider had built a nest in my carburetor which completely blocked the accelerator pump from working. I've also battled with mud wasps, which around here want to seal any small hole they find. An open fuel or brake line during the summer months will be plugged with mud in just a day or two. Geez! Most of the other creatures don't mess with my truck, but do mess with my shop. You name it! Squirrels, Bats, Groundhogs, Raccoon, Skunk, Fox, Rats, Mice, Woodpeckers, Ants, All sorts of bees and wasps, even snakes and toads.

Yep, as stated above 6v starter will work just fine. Mine's been working fine on 12v for over 20years. I once did a stupid thing by hooking 12 volts to a 6v starter on the bench in my youth. without the load of spinning the engine, it rotated so fast that the armature windings bent outwards from centrifugal force and hit the field coils. I ruined a perfectly good starter with my stupidity. Another change you'll have to make is adding a ballast resistor to drop the voltage to your points. I just recently did away with that and switched to an electronic Pertronix ignition. So far is working well, and don't have to worry about the ballast resistor failing / points wearing or oxidizing / or finding quality sets of points and condensers. The Pertronix module is also less sensitive to worn distributor shafts.

My dad owned a repair shop from the early 50s up until late 90s. He had a Ammco brake lathe and shoe grinder. Anytime we turned a drum we would resurface the shoes to exactly match the radius. That's in the days the drums were worth re-cutting. I used to love the smell of all that asbestos flying around. Lols! The machine was in a back room with no ventilation. Anyhow, when we finished a brake job, the cars stopped like new. If your drums are not standard dia. and you install shoes without grinding, they often will squeal and could make the car pull to one side or the other until they wore down to match the radius. Also, some lining materials were more prone to squealing than others. I'm sure there's some that still do this, but beats me where?

As far as I know, you don't! You could get a Mopar 12v generator. I think there's still lots of them around, but I would recommend an alternator. They're just a less problematic. The easiest would be one with an internal regulator like the GM one suggested above. Pretty much plug and play once you adapt the brackets. I installed a 70s Mopar alternator in effort to keep things Mopar. It uses an electronic regulator which I mounted on the firewall where the old 6v voltage regulator was mounted.

Lols! Yep, some loving and attention is what our trucks need. Problem is, it's like a woman, how much love and attention? And where do you stop? Too little you lose, too much you lose. If you figure it out let me know. Lols!

I get confused easily, but I'm not following exactly. ? I'm just a shade-tree mechanic. I believe this is the way to check: ? Standard open differential - With both rear wheels off the ground, rotate one of them, the opposite wheel should spin in opposite direction. Positraction / limited slip differential - With both rear wheels off the ground, rotate one of them, the opposite wheel should spin in the same direction. If you have a standard open differential (which is likely), place a block of wood or something under one of the rear tires and lower vehicle so opposite wheel is free. In this case, if you rotate (pinion / driveshaft) the free side should rotate. You could then mark the axle and (pinion yoke / driveshaft) with a paint stick and then count the turns to approximate your gear ratio. If the wheel does not spin in this scenario, I would think something definitely wrong. Being your vehicle has set for so long, I would suggest removing both drums before checking again. Rusted surfaces might be giving you the "resistance" you're referring too? Does anyone know if and what years Mopar installed limited slip differentials our trucks?

I was thinking same thing as kencombs. Broken axle or stripped spline? Perhaps it was the axle wobbling on the driver side and not a bent drum? Let us know what you find.

I'm relieved! I try to stay Mopar as much as possible, but I must admit, there are a couple of gm and ford parts hiding under my truck. Does it count if they're made in China? Lols! I am however, meticulous about not altering anything I cannot reverse to oem. I'm with you on the Chevys. They do not belong in Mopars or Fords for that matter. Flatheads forever!