If it has the factory Autolite 2 bbl carb that's one of the simplest and easiest carbs there is the to work on and rebuild.
Just rebuilt the Motorcraft version of that carb a few days ago, took about 45 minutes but it's been a number of years so I was out of practice.

What's it doing?

 

What's on there right now? What seems to be the issue with it? The old saying is "90% of all carburetor problems are ignition related." And it's true. Plus, a new carb would still need to be setup and tuned.

 

 

Glad to see someone else has this figured out. This is also why Holleys got the bad rep they had, ditto for multiple carb setups. My vote for the OP's replacement is a Holley 2 bbl. I never had much luck rebuilding the Motorcraft carbs. Plus they're all 40+ years old now. And old carbs are nothing but trouble.

 

Ditch the points setup and replace with a drop in electronic module. Points constantly wear, changing the dwell angle and thus the tune. And if you don't have a dwell meter to set the points with, you're pissin in the wind trying to tune it. The point gap is a starting setting, you have to use a dwell meter to accurately set the points. No getting around this. And not all points sets are alike, the spring tension has everything to do with how long the setting stays set. Weak point springs will stay set longer but will bounce in the upper rpms, this plays havoc with the performance. Stiffer springs are better for controlling the bounce, but they wear faster, changing the dwell setting and thus the tune. Electronic modules eliminate all this. Keep the points in a drawer in case of a nuclear war. That's the best place for them.

 

Especially when the throttle shaft bushings (if the carb even has them) get all hogged out

And if the top distributor bushing is hogged out, the dwell will walk all over the place with points. An electronic drop-in like a Pertronix can mask this condition quite well.

 

My sentiments exactly !

 

 

You've got two sizes to choose from: 350 cfm or 500 cfm. The list for the 500 is 4412. I don't recall the numbers for the 350. The 500 is half of a 750 cfm double pumper, (they're rated at different pressure drops) I've run the 500 on several engines, from 302 to a 400. It's one of Holley's better carbs as far as reliability. The 350 would be better on fuel though as it's accelerator pump is smaller. (30 cc vs 50 for the 500)

 

 

No, it will flow more than a 360 will pull.

 

Itt

Ditto ! The cfm is a rated flow at a pressure drop of 3" hg. The 360 could possibly pull more. If it did the carb would flow more

 

 

When I read about flow and CFM and the rest of it, they always seem to be talking about 6000 RPM, stuff like that. Those are drag racing calculations. It will likely run like **** at anything other than ***** to the wall pedal to the metal. If you plug in your average RPM in high gear at 50 or 60 mph, see what it suggests. Most likely something close to 350 CFM or even a bit smaller. Just what was provided as OEM. Hm, maybe those Ford engineers were on to something!

Trucks were designed to haul heavy loads, starting from a dead stop a smaller carburetor atomizes fuel better, and offers crisp throttle response with lots of torque in the low range where most people do their driving. Carburetor flow differences (mostly) show up at the high end, at high speed anyway. When it comes to carburetors and camshafts, I've read "pick the one you think you want, and go one step smaller."