TRYING TO FIGURE OUT JET SIZE FOR MY TRUCK, 73 F100, 390FE, 2 BBL 2100 SERIES CARB. I LIVE IN PEORIA,AZ. ELEVATION AT 1200 FEET

 

WHAT SIZE ARE IN THERE NOW? IT'S VERY COMMON FOR PREVIOUS OWNERS TO MAKE CHANGES OVER THE YEARS. THE FORD TRUCK SHOP MANUAL WILL PROVE INVALUABLE FOR INFORMATION SUCH AS THIS.

KEEP IN MIND THE CORRECT POWER VALVE SIZE IS ALSO A CONSIDERATION. 1200 FEET SHOULD NOT TECHNICALLY REQUIRE ANY CHANGES FROM THE STOCK OEM COMPONENTS AS SPECIFIED, BUT THE STOCK SIZE JETS MAY RUN TOO RICH OR TOO LEAN DEPENDING ON YOUR APPLICATION.

 

I don't know on a 2100 but my 2150s run 57 jets, 55 are too lean, now I would wonder since my 2100s seem to be slightly larger butterflys than my 2150 but that may or may not require larger jets. airbleeds and venture design effect this as well. I am at 6000 ft and my 2100s had 55 or 57 in them when dismantled, but you may very likely need a size or two on me, more air. I notice when I go up to 8000-9000 feet in the mountains, I don't even notice a rich condition.

 

Is there an ID tag still on your Carb?
Other numbers on the Side of Bowl & on the Base ?

 

Good place to start. Was the truck issued with that particular 2100 carb though? The Shop manual has the carb size... and jet size for that engine.. with the OEM carb.. And Venturi size.. and booster cluster.. After 40 or 50 years no telling what's on there. I'd throw some 53s in it and go from there.

 

I would run between 62-67, and probably settle on a 64. You may be suprised with better fuel mileage once carb and timing are adjusted, plus better cold start performance and power.

You are feeding a lot of cubic inches, with a very big intake to draw the fuel across.

 

Depending on the carb's ID tag number, 1973 F100/350 360's could have: #53F; #54F; #55F or #57F jets.