To determine WHICH carburetor was used on which G.M.C. engine, try here:

http://www.thecarburetorshop.com/TRGMC.htm

Jon.


Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop