Loren

This is a great question. Plymouth in 1952 was the first production car to feature tubeless tires. Looking at a number of older wheels you can see they were ready for them for years. What Plymouth called "Safety rib" wheels are needed for tubeless tires. If your rims have that feature you can try them. The only thing that could be a fly in the ointment are the rivets holding the centers. If the wheels leak at the rivets don't worry there are fixes for that. Not all car makers were as smart about "Safety Rib" wheels and tubeless tires. Hint: Look at present day photographs of surviving 1969 Ford Mustang Mach 1s. Then look at the advertising and brochure photographs. You will note the survivors rarely have their original wheels. The ones that didn't have "Safety Ribs". Don't ask me how I know.

I just sold an 1964 International Travelall that had a T86 with R 10 Overdrive transmission. I've been told the Plymouth Transmission with Overdrive is a better gearbox. I really liked the Overdrive feature especially with a smallish engine. (The IH had a 266 V8) There's a pretty good hill near my home which at about 3/4 of the way up would trigger the kick down. Once you crested the hill and lifted the throttle a little it went back into Overdrive. Getting it into 2nd gear Overdrive took the right situation and practice. I am sure most people wouldn't bother. A flathead Plymouth seems to be the perfect car for an Overdrive transmission. Overdrives have a certain charm to them and Plymouths are cruisers which amplifies that charm. If you don't use the "Automatic" feature of the B-W Overdrive, I think they are kind of pointless. In other words if your Overdrive doesn't work like it was intended automatically, I'd either fix it or get a different transmission. Using it to get "one more gear" is not enough to justify the trouble of having it. A T5 shifts faster, easier and has a synchro first gear. There's not much "charm" to a T5 though. I've driven foreign cars with the Laycock-DeNormanville Overdrive which are not "Automatic". You have to flip a switch or toggle a lever to switch between direct and Overdrive. Honestly, I'd rather have a 5 speed than a 4 speed with non-automatic Overdrive. L-D did not put the governor and kick down switch in because they figured the Overdrive would be engaged under full throttle most of the time. The L-D Overdrive was to be installed in sports cars, while the B-W was designed for full size American cars and trucks. Different designs for different vehicles and uses. The freewheel feature should get some mention. First of all parking the car in gear does not ensure it won't roll. You've got to pull the Overdrive handle to lock the freewheeling. However, if you master it you can shift without using the clutch. You have to let the engine RPMs drop below the drive shaft speed to do it, then slowly raise the engine speed till they match then accelerate normally. I raced SAAB cars in SCORE Desert and Baja races. They had a dedicated freewheeling unit (it was a hold over from the 2 cycle days. Two cycle engines don't get as much lubrication when the throttle is closed, as the fuel carries the lube oil). I loved it as you could down shift going into a corner then power out without touching the clutch. I used it like a kind of "Pre-select". I suspect this has a limited application for a Plymouth as you will never rev one 7,000+ rpm. So the question is "Charm" and highway speed or modernity? You can put a V8 with an automatic in your vintage Plymouth and perhaps a front frame clip from something else for better steering and brakes, but what do you have afterwords? It will only look like a vintage Plymouth. There's something rather 2D about such a car. My choice would be the best example of what was available at time the car was made. That way it retains all of it's charm.

What I would say only applies to my car (1952 Suburban). I recently bought a Plymouth Overdrive transmission on eBay. I had been watching for sometime and the going price for one in unknown condition was $800. This one had been gone through and had a new relay, the wiring harness, kick down switch and as a bonus the drive shaft. It had also been set up for 12 volts. It was near by so I picked it up myself saving a shipping bill. I paid $1,100 and figured it was a good deal. Overdrives became available around May or June 1952 for the post war cars. The B-W Overdrive reduces engine speed by 30%. There are calculators on the internet for tire rotation per mile (for commonly available modern tires) and final drive ratios. A friend gave me a rear end from a 1954 with a Powerflite transmission. This was a cheap and easy way to get a lower numerical ratio (3.73) and all of it is stock stuff. It's just arranged in a way the factory never intended. Factory built Overdrive cars used 4.1 final drives which gave them better acceleration but didn't give them top speed potential. Now something to consider, is that one is not going to "speed shift" a Plymouth transmission (or any 3 on the tree Overdrive for that matter). I have a T5 in a Model A and I don't care for the ratios at all (I am told there are other ratios available such as for a Camaro) but it is modern and does shift quicker with less drama. So that is an option. For me I was not going to cut a hole in the floor of my car for a shifter. So three on the tree works for me. Gear ratios will get you to modern Highway speeds but.... will your engine have the torque to pull them? Which means now you have to do some engine work. One thing I haven't heard on this site is the idea of restricting the size of the holes drilled in the block to the cam bearings. The oil passages go to the cam bearings first and then to the Crankshaft main bearings and finally thru the crankshaft to the rod bearings. Many production engines are that way (even the mighty Ford FE 427 that won LeMans). For racing there are kits for these engines to restrict the flow to the cam bearings which sends more oil at greater pressure to the crankshaft main bearings. Plymouths have oil passages about .250" the common restrictor size is .065 to .070. So you see there's a lot to be gained! There are no secrets to getting more power however keeping the engine alive is of greater importance.

Of all the 1949-54 Plymouths I have had a love of the Suburbans. Woodys are nice but just don't have the purportions of the Suburban (they were on the 118' wheel base). K.T. Keller I believe had a great idea when he made Chrysler cars with "chair height seats and enough head room you could wear your hat". As I get older I appreciate taller cars, they are easier to get in and out of. In retrospect some have called the Plymouth Suburban the first SUV. Certainly the SUVs are giving mere "cars" a run for their money in the market place now days. Some may recall the Suburban with the floor shifted 4speed and 18 inch wheels, (as seen on this site) now that was an SUV! This thread made me to go over to my warehouse and "visit" my 52 Suburban. The rats have been using the front seat materials for nest making...but I planed to re-upholster it anyway. I found the original seats a little plain. Today I drug out a rear end from a 54 that had a PowerFlite transmission. It's a 3.73 ratio and coupled with the Overdrive transmission I just bought should get the highway RPMs down to modern standards. I know I guy who is putting an early Hemi in a DeSoto. He's promised me the engine so I might have enough cubic inches to pull that gear ratio.

I think Dan Hiebert has the right idea. I might try the factory setting First as a baseline, then a degree more positive and if all is well then the second degree. If you're lucky to find an old timer, he's very likely already done a 1949-54 Plymouth several times and knows exactly what works. If I still lived in Southern California, I know exactly which alignment shop I'd go to.

Just my two cents. If you go with Radial tires, you might want to consult with a real good alignment shop (or several). Radials respond better to more caster than Bias Ply tires. Seventy years ago engineers only had Bias Ply tires to work with and their focus was on extending wear, which was in the 15 to 20,000 mile range if that. WiKipedia, that great oracle of knowledge says radials like 7 degrees of caster where Bias Plies like considerably less. We live in the 21st Century and our cars are forced to deal with what is available at a reasonable cost, might as well help them adjust to modern reality. From the Plymouth Manual Caster is -1 to +1 with Zero preferred, which is a long ways from 7 degrees. My knowledge is pretty dated (I last worked in auto repair in 1986) so I am a little fuzzy on Caster vs King Pin Angle (which is 4 3/4 to 6 degrees). Seems to me they basically do the same thing, just in a different place (one adjustable and one usually built in). So adding 1 degree of Caster might satisfy the tires and still remain within the specs.

In regard to fitting the hubs to a keyed axle. I have found that Low Strength Loc-Tite is the way to go. It seals the moisture and dust out and provides good metal to metal contact AND it makes it easier to get apart next time. I speak from experience gained in off-road racing. We had problems with wheel bearings on a front wheel drive car. We used new axle nuts every time we replaced a bearing and after only two races, they had to be cut off as the alkali dust welded them to the axle. Low Strength Loc-Tite sealed the threads and made the nuts come off much easier. Used on splines and the O.D. & I.D. of the bearings made them fly apart by comparison. Usually you think of Loc-Tite as a means to keep things together and it does that very well, but I used it to be able to get things apart again! In regard to brake bleeding. It is far better to PUSH the fluid through the system than any method involving SUCKING. I would pressure bleed Master Cylinders on the bench, then install them on the car, without bleeding the whole system. Done right and all you need is a couple of pedal pumps and you're done. If you need to bleed the whole system then start at the furthest point from the Master Cylinder. Open that wheel cylinder's bleeder (if you have a hose and a catch container, use it) then fill the reservoir (use a pressure bleeder) or just put the cap back on and apply a small amount of air pressure to the vent hole. Fill the reservoir again, then close the bleeder and repeat with the next farthest bleeder. Note that it only takes one person to bleed brakes fast the first time.