well im not too worried about gasmilage seeing that i already and getting about 8mpg and really want to get rid of my stock 4bbl and get the ole pickme up to open up a little better. im debating right now over an edlebrock 600cfm or a 750cfm and dont want to get anything too big but i dont want to starve the poor baby either.

 

Tell us more about the truck. What engine, tranny gears, model? What do you want to do, race, tow, freeway flyer?

Just picking a carb takes more than just wanting to open up better.

Need to know more. Some of our experts can give you really specific info, if you help them along.

Jim Henderson

 

I have a dead stock 79 460 with headers and a weiand stealth intake. I put an edlbrock 1407 750 cfm out of the box and it runs great. From my understanding they both run about the same, except the 600 will run out of steam at about 4000-4500 while the 750 will pull a little harder in the upper rpms.

 

OK, in general a 750 is a pretty good size carb for a mildly modified or near stock engine.

Still comes down to what do you want to do and what other mods do you have?

I am not reall knowledgable about Ford engines in particular and especially late 70s smog engines. The newer 90s 460s were not real good above about 4,000-4,500 RPM without mods. There were also some limitations above that RPM due to the piston rods.

If you just want a more powerful street engine, I think the 750 is a good ballpark. If you were running higher RPM(more than 5,000) and or a hot cam and high compression you might go with a bit larger carb. A big carb(say 850 and up) would hurt torque at the low end unless you had other mods. Torque is what you want for every day trucks.

I do not know the specifics of the Edelbrock carbs, but in general for street driving, if you could find a spread bore carb(small primaries, big secondaries) you would get good mileage and peppy low speed performance(good torque) and then good performance at high speeds. If the Edelbrock is spread bore, I think you have the solution in your hands. Even if it is not spread bore it is still a decent compromise.

What is the powerband of the Weiand Stealth manifold? That can also guide you as to how you want to do things. If the powerband is above 5,000 RPM, then you probably need a bigger carb and some engine mods and gears. If it is between say 2,000 and 5,000, then I think you are properly set up.

There are always tweeks and minor adjustments possible, but I think you are close assuming you have a daily driver.
Good Luck,

Jim Henderson

 

I have always run in drags at least 800 cfm double pump Had to install two eletric fuel pumps on my 660 cfm carbs when I ran my 70. So go BIG and it will work Haakeye