well i say on bubba's web site that he has the 2150(yupers same model) motorcraft carb off a 82 mustang GT
that runs 369cfm(vs 310 for original), variable (i.e., tunable) high-speed metering system(vs fixed high-speed metering system), 58 main jet(vs 53), and a better power valve calibration
i am looking for 1 now for my near stock truck
that bubba is a sharp 1 bound to be cheaper than a holley 2bbl and for just swapping/rebuilding the factory carb
he also unpluged the egr and put a 63 main jet in and still passes emmisions "2 speed idle test co and hc only" what ever that means lol
finally i shall quote again, ""The richer mixture has eliminated all off-idle and part-throttle bogging, and it vastly improved the cool temp driveability. The richer mixture also helps prevent the pinging for which all M-block engines are notorious""

soulds good gonna try as its cheaper than a edel even tho i have a 750 waiting thats way too big and have to find 600 edel/625 carter BOTH made by fedral mogal and close to the same design and a good intake

 

Well, personally I would start from the foundation and work out. the first thing I would check is slack in the timing chain(sounds like to me you might have slipped time or about to). Especially if it's an original engine. Starting in 74 or 75 Ford went to vinyl coated timing gears to reduce noise.Over the years the vinyl wears and major slop occurs in the chain. Check this before doing anymore timing checks, you could wind-up over compensating with your dist. timing. One way to check this is to pull your dist. cap and rock your crank back and forth to check how much it moves before the dist. moves. If it's over say a few degrees pull the front end of motor and check it out. The only carb adjustment that could be made that would cause your problem(again an uneducated guess) is possibly a misadjusted float. Causing the motor to run super-lean(pull plugs and check color). the reason why I say check this I have a 400m that someone did this with over advanced the timing to compensate for the slop in timing burnt two pistons(BEWARE)Hope this helps.

 

Thanks all for the great info.I will try to do this asap.

 

Quit trying to make it fast. Go back step by step and see what you changed, then unfix what you fixed. The factory tune is a really good place to start.

Now you say it is popping. Is that out of the carb or in the exhaust. Is the exhaust sooty and black with a really gassy smell? If it is, then you are getting too much fuel and the fuel is igniting once it gets to a point in the exhaust where it can get air to burn. That or the ignition is really retarded. Have you been setting the timing by ear, or with a light? If by light, have you checked the damper to see that the ring hasn't moved. Do this by checking top dead center through the spark plug hole on # 1 cylinder. You can read about how to do this in a lot of books. If you don't have black sooty smelly exhaust, and the timing is good, then you aren't getting enough fuel. You say this got better when you tightened the carb down. That's not a good sign for you not having a vacuum leak. Have you checked the egr valve and all the hoses for a leak? Any hose can have a crack in it and cause a leak. When you were checking the egr valve did you check the housing to make sure that it hasn't cracked or burned through somewhere? Now that you have done all of that, did you change the firing order of the spark plugs when you were tuning it up? It's really easy to do when you are in a hurry. Have you checked the vaccum advance can. Suck on the hose and see if the arm moves. If it does, then put your tongue over the end of the hose and see if it holds a vaccum. If the arm slowly goes back, you may have found your problem. Now that I think of it, some of your symptoms are exactly like a failed vacuum advance can... If all of that checks out, then it's time to pull the carb apart, and put a kit in it yourself. If you can't find anything wrong anywhere, then go find a carb that works on somebody's truck and borrow it. If it cures the problem, then there may be something internally wrong with the carb.

That's all I can think of for now. Try these and see what happens, if you still have problems, then come back and we'll try again.