PT81PlymouthPickup

I was just thinking why have I not seen Don commenting on my infrequent posts. Now, I know why. ? I will miss his advice and humour. My condolences to his family and others on this site that will also miss him.

Well, I guess that depends if you enjoy doing big projects, your skill level, and how much time and patience you have. I am a machinist by trade. I enjoyed doing it, but yes it was a hassle and took a lot longer than I expected. I removed the bell housing and drilled and tapped mounting holes on a milling machine. I had the drum emergency brake on the rear of my original gearbox, so I also installed a differential out of a Jeep Cherokee in order to get emergency brakes along with more modern self adjusting rear brakes and better gear ratio. This required repositioning the spring perches (welding) Had to fabricate a emergency brake mount and custom length brake cables. Custom driveshaft was needed. Fabricated a new floorboard. There were several smaller issues as well. I'm also too fussy for my own good and that added to the time it takes me trying to get everything looking perfect. It was an effort, but my truck is much more fun to drive now. I have no regrets. There's lots of information on installing S10 T5s in our old Mopars.

My 39 Plymouth PT81 was non syncro. It was not fun to drive. I imagine if I drove it everyday and got used to double clutching it probably wouldn't be so bad? I really struggled with downshifting. I ended up installing a Borg Warner T5. It's much more pleasant to shift and drive now.

In my quest to figure out engine stumbling at mid range rpm, I discovered my distributor bushings and shaft are worn out. Not positive it will be the cure, but definitely needs to be repaired. Excessive lateral play at .013" and also the governor weight pivot pins were shot to the point that the weights are beginning to dig into and catch on the base plate which is mounted to the shaft. Here's my dilemma; During this exercise I've also discovered the distributor in my truck (IGS-4003-1) was not the correct one for my 39PT81. It's listed for earlier Plymouth cars. So, I've procured a IGS-4103 which is what should be in the truck. Unfortunately, it's in worse shape. I also had laying around a later IAT-4011 which has a good shaft and looks like it will work in the earlier distributors. It has a different, but more robust governor setup. (larger pins). I may be asking for trouble by mixing things up, but sure looks like it may work? Opinions or advise would be welcomed. 1st image is IGS-4003, 2nd is IGS-4103, and last is IAT-4011. Notice the difference in springs. The IGS-4103 has springs of different sizes which concur with my dodge master parts catalog?

Would have been a lot easier if I had tubing. I made it from a piece of round stock I had laying around. Lots of chips! The clamp came from McMaster Carr.

Yeah Ken! I overthink everything too. And, I also thought this should be a "simple system". But somehow, for me anyhow, these simple things always seem to get really complicated. Lols!

Here's some pics of what I'm attempting. Basically, I've just transplanted the system off the later model military engine. I'm in process of making an adapter between the carb and the air cleaner housing. It's almost done, but I need to silver solder the boss to my adapter and drill and tap for 1/4-NPT. I've also ordered a oil fill tube from vintagepowerwagons.com that already has a fitting and also a sealed oil fill cap. Once this is done, all I need to do is plumb them together. I hope! Lols!

Not sure what you mean about "a small vac.passage that is needed by the carb." I'm thinking of making a spacer between the carburetor and the air filter housing then attach a 1/4 NPT fitting. Attach a tube to it and the other end to the oil fill tube. This is what was on the military engine I have. I'm unaware of any vac. passages?

Thanks! Your comments got me to thinking. I have determined that my distributor housing is listed for earlier (1935-36) cars, but the breaker plate is the correct one for my 39 truck. Obviously, some of these parts interchange. The cap and rotor are listed the same for the distributor I have and also the one that's supposed to be in the truck. I'm totally confused by this dizzy stuff. I've found some on eBay that have the correct numbers but different letter and dash #s. For example; 1939 Plymouth PT81 should have distributor IGS-4103A-1 or IGS-4103B-1. I found one #IGS-4103 on ebay but with no letter or dash #. I was hoping someone on P15d24 might explain what all these variations might be and how important is it to have the right one for a particular vehicle?

Yes, I think that might be the most likely possibility. I also was told years ago that some of the professional engine re-builders would remove the numbers? Hard to say! I just discovered that the breaker plate in my distributor is the correct one for my 1939 truck, but the distributor housing is listed for earlier (1935-36 cars). Obviously, some of the parts interchange, but not being very knowledgeable on these distributors, I have no idea how important it is to have the correct distributor for the engine. I'm uncertain as what might be my best path? Get the correct one for my truck? Rebuild the one I have?

In my struggles to figure why my engine runs roughly at partially open throttle and with help from searching on P15d24, I have discovered that the distributor shaft has more clearance than feels right. I measured with a dial indicator and it's wiggling at .012". That seems excessive? Anyhow, I'm not certain if this is the culprit to my engine falter at higher rpm, but I want to fix it regardless and just maybe I'll be lucky? According to the 1947 edition Autolite service parts catalog https://www.thecj2apage.com/storage/47_autolite_service.pdf my 1939 Plymouth PT81 should have had a IGS-4103A-1 or an IGS-4103B-1 but the distributor that's in it is a IGS-4003-1 which is an earlier one listed for 1935-36 Dodge and Plymouth cars. Unfortunately, I have no idea what my engine came out of? The numbers on the block were removed. I'm guessing that it may have been an earlier engine that was re-manufactured? Perhaps that's why the earlier distributor? My conundrum is what to do now? Install new bushings? Try to locate another distributor in better condition? Which one? Does it matter? I was thinking of installing a Pertronix unit or Langdon's mini HEI? I like the idea of not having to service points and getting rid of ballast resistor. Perhaps this is the time, but the more I read about those options the more confused I become. Opinions and advice welcomed and appreciated.

I ordered from Rockauto a Fram CA6605 (cross referenced K&N E-4655) which has the dimensions that I think will fit my air filter housing. I'll post the outcome as soon as it arrives.

Yeah! I'm all for world trade. And I don't think outsourcing is bad thing. Competition inspires innovation and keeps costs down. The Japanese woke our automotive industry up in the 1970s when U.S. quality was going down the dumper. I do however take issue with trading with communist dictatorships. It's all about profits and access to populous markets. I'll bet if we could raise the dead and bring back the Roosevelt's, they might not tolerate the stupidity that goes on today on this issue? Anyhow, sorry for the political crap. Just had to say!

Probably all made in China? Lols! Seems like there's hardly anything new I purchase does not come from China no matter what American corporate label it has.

Thanks Pete, I think that might work from the measurements I've taken. I found from the K&N website that the K&N E-4655 has similar dimensions with cross references to several other brands that cost less. Perhaps that will work as well?

Thanks JBNeal! Very helpful. I read Grey Beards posts and it seems an identical issue to mine. I have not had my truck on the road since I added the pcv valve, but will in the next few days. Just seemed a bit of faltering when hold open the throttle in the shop. I was also thinking of enlarging the main jet. I think I will add a tube to the air cleaner before I explore other pcv valves. The valve and plumbing came off a 230 cu. in. engine which had a Carter Ball & Ball ETW1 carburetor. I'm not positive now what displacement my truck's engine was originally, but we did bore it over-size (over 30 years ago) so, I'm guessing around 220 cu.in? I wouldn't think that small of a displacement difference would affect it? I'm guessing that the carb on the 230 military engine was likely jetted larger?

I have this oem air cleaner housing that was the standard one for my 1939 truck. It's been repainted and in perfect condition. I would like to use it, but can't seem to locate any filter elements? It's listed in the 1936-40 Dodge truck master parts catalogue part #591387. There's no flat surfaces which I think might not accept a standard round paper filter? I'm thinking perhaps the original elements for these were not paper? The parts catalogue does not list the element separately. Anyone have any knowledge on these or paper elements that might fit it?

Just finished installing a pcv valve (AC CV-698C) from a 230 cu. in. military surplus (built in 1967) engine into my 1939 Plymouth pickup. I'm uncertain as too the exact year of my engine? Anyhow, after installing it, I needed to adjust the idle mixture. The engine seems to run slightly rougher at higher rpm (around 1500 or more) Any opinions on this? Another question; is it OK to drive without the tube going to the air filter? I'll need to do some fabricating to do this. I plan on converting to a paper element filter as well. It's been my experience just about every time I modify something, it rarely goes smoothly. Has anyone made this modification and offer any wisdom?

I don't think it's the valves, but I am going to adjust them this coming fall or winter. It's a bit of a project adjusting those buggers. Should be done running and hot and the only way to really do that on mine is pulling the inner fender.

I replaced the fuel pump about a month ago with one I purchased from Rockauto along with a new filter and hoses. Seems OK, but I wondering if the Chinese that built it sabotaged it somehow? Lols! Seriously though, isn't a shame we can't make anything here anymore considering the quality of the stuff the U.S. used to be capable of producing.

Thanks! Full throttle travel is fine, but I have not inspected the jet or metering valve yet.

Yes, I agree. I did check the mechanical advance visually and seems to be in good working order and the vacuum advance also meets the distributor spec. when checked with timing light (about 11 degrees max. at higher rpm) I'll take a look at Advanced Distributors.

Absolutely no offence taken!

Yes, it's been parked way too much. Life's been too busy. Even so, I have maintained it fairly well and kept fresh fuel in it. I took the top off the carburetor and it looks pristine, although it might be wise for me to take it apart and blow out passageways? I've recently have more time to devote, so I'm hoping to get everything ship shape and drive it more. I too like the slant 6 conversion except for it requires mounting a module somewhere with additional wiring. The purist in me does not want to drill any mounting holes.

Yes, you are right, it no longer qualifies as "restored". I did "restore it as pristine as I knew how back in the 1980s and found it was a bit of a pain to share the road with modern vehicles. It's a bit safer and more fun to drive now. I think of it as a resto - rod. I do have all the original parts and made certain not to make any modifications that could not be easily reversed. So, I hope purists don't get too angry at me? I also try to keep it as much Mopar as I can. I appreciate the engineering and skills of some of the street rod guys, but I must admit I get furious when they cut up a perfect vintage vehicle. Seems like a crime!