Vacuum advance.

[Mertz]

I have a non-functioning vacuum chamber on my distributor and didn’t want to spend $150 for a new one. I was going to run without until I found some on eBay for a reasonable price. Does anyone know what part numbers work with my 1940 Plymouth truck? There are a number of unit for 57 and newer cars that are reasonably priced and appear correct. I also have one listed for earlier cars that is an autolite vc2082r which I’m leaning to. 

[Jerry Roberts]

What is the Autolite part number on your distributor ?  The part number often starts with letters  . 

[Mertz]

 

looks like SS 109-1. 

[Jerry Roberts]

2 hours ago, Mertz said:

 

looks like SS 109-1. 

 

[Jerry Roberts]

The correct vacuum chamber for your distributor IGS4109 is part number VC-1039A . This is for 1940 Plymouth truck model PT 105 . Also note the same part and distributor fit 1940 Dodge truck model VC and Plymouth cars model P9 and P10 . 

[Jerry Roberts]

I see one on ebay for $35 . Item number 335414694008

[Mertz]

I couldn’t find the item number you listed. I think I found it and was also looking at another one also $35 but different part number. Is the one you are referring to?

[Jerry Roberts]

Yes , that is the one that i was referring to . VC 1039A

[Robert Harrison]

I suspect a lot of the various chambers will work assuming the housing and linkage fits, if it is from a period small block to small block or big block to big block six.  I suspect the only real difference then is the spring tension inside that counters the forces of the diaphragm.  Trucks probably have more conservative spring tensions meaning slower or less advance due to the fact that they are to carry heavier loads but if you are not as most of are not using them for work vehicles you might actually see an improvement in drivability.  A similarly weighted sedans chamber would probably work just fine maybe even better.  Many people have swapped in motors from other Mopar based vehicles without giving the distributor and advance any thought at all. All small block 218-230 6 engines basically use the same distributor  while all big block engines 237-to 251 or so used in Chrysler, Desoto and Big truck use the longer distributors.  Military engines likely had no advances I guess they had a big wallet as the advances help with gas mileage.  

[Jerry Roberts]

[Mertz]

I received the VC1039a and it will not work in my distributor. The offset is way too big. What I need looks more like the VC2042 in the picture above upper left. I believe the seller had the wrong unit in the box marked as a VC1039a. The 1039 sold on other sites look more like the one I need. I contacted the seller about the issue. 

Edited July 3, 2024 by Mertz