I have an 85 f150 with the 351w H.O. What size carb came on those from the factory? The motor is pretty much stock I believe ther then an edelbrock performer intake and long tube headers into a single exhaust with a cat. It has an edelbrock 750 on it now, but it seems like something isnt rite with the carb thats on it now. I have a holley 600 square bore with vacume secondaries, and a quadrajet marine 750 thats a spread bore. Would either of those two carbs be better then the edelbrock?

 

Despite the HO designation these smog motors only made about 200hp so I believe the OEM Ford carbs were 600, a 750 would probably just cause driveability issues.

 

The Edelbrock 750 should work, just not as well as the Holley 600. Forget using the spreadbore.

 

It would work with the secondaries completely disconnected. The 600 vac is the right answer here.

 

Yea, but only with an adapter.

 

I put the holley 600 on it today, what a difference. The truck runs sooo much better, and smoother. Actually has more low end power. But my gas pedal bottoms out on the floor/ carpet/ insulation preventing full throttle. It doesn't have enough throw. It almost looks like the pedal might be bent. I'm gonna pull it off the truck n see if I can straighten it out.

 

Move the throttle linkage ball farther up on the lever of the side of the carb. It's probably too close to the centerline of the throttle shaft.

 

Thats what I initally thought, but the gas pedal was bent/ bent it back and welded a little support on it to prevent it bending back over time.

 

the spreadbore carb will not work on the square bore manifold without an adapter, and you are not going to use a adapter, right?
Now that we're stuck with the square bore 600 i would sell both of them and get a edelbrock 600
Edelbrock.com - Carburetors & Accessories - Performer Series Carburetors
or 650
Edelbrock.com - Carburetors & Accessories - Thunder Series AVS® Carburetors in 650

the 650 will grow with the motor and allow you to make significant changes without changing the carburetor, did i mention how easy it is to re-jet an Edelbrock Carb, super simple with their strip-kit. Will Carter created these carbs when i was in high school and edelbrock just bought the patent and tooling, of all the WCFB's (will carter four barrels) t's the Thermoquad i miss the most, legendary carburetor..