Any motor heads out there?

I've been an engine guy for my whole life, rebuilt a bunch of racing and airplane engines, so I guess I qualify as a motorhead   not a bad idea to open it up once in a while. The only place fuel will sit is actually in the main jets to the  top 2 barrels, the float chamber is common to all 4 usually. It won't take long, there isn't much fuel in that passageway. Truth is, it will gradually bleed out just from air leakage, but opening it up once in a while will do it faster, besides fun. Can't answer your other question though. I believe Holleys were standard on those, so there is that.  

When I did a full restoration on a ‘68 Firebird I got rid of Pontiacs ported manifold and used an Edelbrock intake manifold, with the proper adapter/spacer with a Holley 850 double pump carburator/4 barrel. Constantly tweaking the mixture. Finally I installed an in-line gas filter alongside the carburetor and the end result was worth the effort. No more bogging down. I made sure at least twice a week I’d get on it a bit and blow out all 4 barrels of the 850.

I had to sell it during the gas crisis of 1973. My first wife used it for commuting while her Pontiac was in the shop. She got this wild look in her eyes when she got in it. Supreme power on the freeways.
I needed money, it needed a fuel pump, and a guy offered me $850 for it. Just don't say a word.

An education on AFB carbs.

www.thecarburetorshop.com/CarterFourBarrelCarburetors.htm

And a 600 is probably too big for that engine in a truck.

Quadrajet set it and forget it take a welding tip cleaner to the back jet to upsize em a bit. Holly has always been over rated but they used to be cheap I see not so much anymore. The OEM 2bbl carb was probably about 425cfm and yes Ford loved 2bbl carbs. If the truck has a mild RV cam it will use every bit of 600cfm. The 351m heads are what hold it back such a terrible design. The good heads are 4bbl Ausssie head and good luck finding those. Be happy it is not a 351W those had small valves and big smog ports hanging down on the exhaust side and just could not breath. The exhaust system on the truck is plenty and unless a manifold cracks is not worth headers, Melling offers a nice kit www.melling.com/parts-lookup/ costs 150 bucks not bad for a cam and lifter set and it will work with the stock springs and press in studs. Oh and you would want new valve keepers. Still cheaper than playing guess what carb I need and finding someone to properly set it up. Now the carb you have will match the cam you have and the truck will have a better power band and just a few more horses. The 79 ford had the square headlight instead of the round up front and is a good looking truck.

This is what I mean

That's pretty fuel good mileage for a 4x4 of that era so yeah take her out and make her bark. That is to say blow the soot off the exhaust valves.

Did someone say Motorhead?


Yes yes I am a gear head...

Depends not the underwear the Autolite/Ford 2100/2150 came in all kinds of sizes depending on the cam and they used those 2bbls for almost 30years. The 4bbl were the 4100/4150?. Remember OEM is about compromise or balanced power and a balance of longevity of other parts of the drive train. They came in 8 sizes 0.098 - 190 cfm, 1.01 - 240 cfm, 1.02 - 245 cfm, 1.08 - 287 cfm, 1.14 - 300 cfm, 1.21 - 351 cfm, 1.23 - 356 cfm, 1.33 - 424 cfm and that does not account for the various jet sizes just the air flow. There are very few folks around who fully understand the Ford part numbering system. Everything is not all the same even though it fits. Take a look at power valve they all interchange between Holly and Autolite at one time there were hundreds that has been condensed down to a dozen part numbers. How can that be, Autolite carbs are Holley in disguise. The Holly 4150 was stock on the Tbird But Ford wanted a one piece body because the 4150 bowls leaked like a sieve that's how the 4100 Autolite came about a one piece body set it and forget it. Autolite 4bbl starting with the 352 are 600cfm man the money you could have saved.

The carbs are easy to work on. You can clean it in the kitchen in a couple of hours and put a kit in it. If it was tuned to your engine when you got it you should still be good. Count the turns to tighten the adjustment screws before you remove them. If it's really dirty you might had to use one less turn out from where it is. I have done this dozens of times and it should fix you right up. Triple check all vacuum lines and plugs.