!!!! LOW TIRE PRESSURE CAUSES PROBLEMS ON CLINCHERS  -  COME ON SPRING !!!!*
Here is some surprising info found on the Model T Forum I thought was interesting. The question was why his Model T valve stems were failing. The answer is:
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ANSWER: Usually a valve stem failure is caused by one of two things - the tire slipping on the rim, carrying the tube with it, or the tube it self "sloshing" in the tire. Both of these are usually caused by insufficient pressure - clinchers take 20 p.s.i. per inch of width, so on 30 x 3 1/2 tires you need 70 PSI. (3.5 X 20 = 70 PSI)   If you go with a standard oversize, which is 31 x 4, that puts it up to 80 PSI. (4 X 20 = 80 PSI)
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Dont underinflate clinchers.... a lot of people seem to think 40-50 PSI is OK and wonder why they have tire problems.  Clinchers are high pressure tires and designed to run in that way.
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There may be another, tho... If your rims have been powder coated, the slickness of the finish *can* cause the tire to move even at 70 PSI.  You may need to "de-coat" insides to get rid of that glass smooth finish in the rim where the tire sits.
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One reservation I have is if your tires have a lot of age on them the sidewalls won't hold to this theory. 

   Here are some part numbers gathered over time for my 1929 Plymouth. Even though parts for these cars dont show up very often it is still handy referance. Happy Motoring!!!! - Rich 

   This A.E.A. Tune-Up Sheet for Plymouth 4 cyl. 1929 1930 is handy to keep under the seat. HAPPY HOLIDAYS!!!! - Rich   

Here is page 2 reposted as PDF file.

Reposted as a PDF file . Found in an old car parts book.

 ::)This is page #2 of previous posting. Hope it works. - Rich

  I went out to take the dog for a walk and Rosie and I went by the garage and noticed the doors were swinging in and out and rattling !!! I heard metal rattling !!! There was the smell of exhaust in the air !!! Rosie's ears perked up !!! She looked at me - I looked at her !!! This is the garage were I keep my 29 Coupe -  behind that door. My thoughts immediately went the movie CHRISTINE ! Waiting for the door to come down and a WILD 4 cylinder to charge out !!!!  And then it started raining and the wind stoped blowing, the doors quite swinging making noise. I opened the door and the little Black Coupe was just settin there waiting for spring. I will blame this story on cabin fever. I still think the coupe wants out.  Oh well  - Have a great summer! Rich     

  HELLO to everyone. Wanted to go on record to say GOOD LUCK with the new web sight. Our numbers are few now but that will change and be more interesting as more members join in. I have a 1929 Plymouth Coupe U model and got to drive it the first time last fall. After a few repairs and etc. it is finally running. I found out some information that might be of interest to these members. More on that later. HAPPY MOTORING !!!! - Rich