7044240 - Jetting for a '73 FE Ford 390 w/'68 Heads

[65WildCat]

7044240 Question -- Correct Jetting for a '73 Ford 390 w/'68 Heads in a '76 F-150 Long bed - Bored .30 over - Have a 4 hole adapter approx 1" tall, Cold Ram Air Cleaner w/dual 4" ducts to outside inner engine bay- not direct Ram, Eldebrock Performer Intake, MSD Spark Box, Jacobs Coil, High Compression Pistons, Stock Rv type cam, Hedman Headers w/Dual Flowmasters - 2 1/2" w/H pipe running to rear bumper - Towing Converter, Auto C-6 Trans, Np 205 Transfer Case - 4 Wheel Drive w/4.11 Gears w/lockers and 33" Tires... Runs on the Street, my work truck....

Pulled apart carb and found #73 Jets with 49C primary rods - Secondary "T" Hanger with "C" Secondary Rods as read off the parts. Looks to be and I would guess the rest of carb is stock... I have no way to measure all the small air bleeds ect....

Jim

[Cliff Ruggles]

The stock .073" main jets will be close.  If you are able to free up the APT screw in the baseplate it will open up tuning options.

I would install smaller secondary metering rods as well.....Cliff

[65WildCat]

Thanks for the reply Cliff,,, I gave it the old school try to free up the APT screw to no avail.... Soaked in Mineral Oil, added heat... Even broke one side of the screw head off...  Those are a real pain..... For Now,, I just reinstalled the plug cover.... Would have been a nice extra since I just installed the primary bushings for it... Maybe I'll look at it later and see about drilling it out... Or, do you recommend to just leave it be... Do you sell replacement early APT screws.. I need a few other things from ya anyways.....

Jim

[65WildCat]

O.K. ---- Got it figured out....  Thanks for the advice.... and reminding me 'bout that darned screw... Just needed a bit more time to figure it out.... I'll call ya next week for parts.....

Jim

[Cliff Ruggles]

Yes, we have special APT screws for the early carbs that we make here in the shop on our lathe....Cliff

[65WildCat]

Is there a difference besides the screw heads in using the 1965 - 71 idle screws and the 1972 - 78 screws in a 7044240. Are the tips different? I was shipped the earlier ones and am just curious if these are ok to use or should I get the correct year style for usability. Thanks for the great service and products... Jim

[Cliff Ruggles]

Yes, we make external APT screws for those on our lathe, so they can be adjusted like an idle mixture screw.

It's tough to get some of those APT screws out of the baseplates.  I'm 4 for 4 this week on them!  I always attempt to get them out and use an external APT screw, makes tuning a snap when it's back in service.........Cliff