View Single Post
Old 01-13-2021, 03:03 PM   #15
1948F-1Pickup
Senior Member
 
1948F-1Pickup's Avatar
 
Join Date: Oct 2015
Location: Socal
Posts: 795
Default Re: Help decipher GM distributor vacuum canister numbers

Quote:
Originally Posted by Kilohertz View Post
Hi folks,

I'm in the process of restoring my 49 Ford F-47 with the 239 flathead, and am starting by getting the engine running nicely. It hasn't run in years, I have it running now and am starting to make some mods.

I decided to start by machining a GM distributor to fit in place of the Loadomatic. It turned out great and engine fired right up...I am now fiddling with the fine tuning of advance both mechanical and vacuum. All of the references I have found are quoting NAPA/Echlin parts numbers, the VC1765 type etc. I have been unable to find any cross reference to the original GM numbers, and of all the GM dists I have here, none of them have NAPA cans in them, they are all original.

Has anybody found a list of vacuum canisters that reference the original numbers such as are found stamped i.e. 503 15? I know the 15 indicates total crank * at full advance but I want to know begin "Hg and final "Hg.

Any help would be greatly appreciated.

Cheers

PS for now I have an adjustable timing light and hand vacuum pump.
I just completed setting up my GM distributor from Charlie a little while ago.
I used the Crane adjustable vacuum can (99601-1).

I followed the guidance on the pdf attachment.

On the STOCK GM canisters, on the two numbers you mention on the canister mounting bar, the three numbers usually signify the last three numbers of the Delco-Remy/GM part number and as you stated, the last two numbers signify the number of CRANKSHAFT degrees the vacuum advance can allows. The real trick is knowing the first 4 of that long GM #......
Attached Files
File Type: pdf GM Distributor tuning 11-17-13 (1).pdf (575.7 KB, 36 views)

Last edited by 1948F-1Pickup; 01-13-2021 at 03:30 PM.
1948F-1Pickup is offline   Reply With Quote