I have a 65 ford f100 powered by a ford 302 that Im wanting to wake up. update. and get right.

the current setup is
Melling MTF 1 cam
Stock heads re worked and re valved ( i don't have cash for new heads )
rebuilt engine block and hypereutectic pistons
Edelbrock performer intake
500 cfm Edelbrock Carb
HEI distributor
HD truck Manifolds... I had long tubes but they would not fit.

This has been on for almost 8 years and its starting to show it..
the carb is acting up and the intake has a stripped carb flange ( dont know how that happend ) and is leaking a bit at the rear.. the HEI is too tall and im running spacers top and bottom of the carb..

I know its a mixed bag as far opinions go on carbs, cfm, so on..

The carb that keeps coming up that makes sense but not sure... is the holley street avenger 570 and either the performer air gap dual plane and the msd or summit ready to run dizzy.. and mustang shorty headers.

Thoughts... opinions?

 

I agree with the carb (570 SA Holley) intake ? Any of these: RPM, RPM Air gap, Weiand Stealth, Ford C9OX, Ford A321, Edelbrocks old F4B. (first two are equal length runner intakes, last three are unequal length runner intakes) Also there's Edelbrocks old Twisted Torker single plane. Dizzy ? Just a plain old reman points type with a Pertronix unit or any other drop in electronic sets that replace points. Or a Duraspark setup. The MSD stuff just plain costs too much for what you get. (nothing over the two I listed) Never looked at the Summit dizzy to comment on it.

 

Thanks.. there are too many choices and no clear winners. I read a lot of good things about proform, Quick Fuel, Demon and Summit about how they have corrected the things
that holley got wrong... and not for much more money if any really. I think my engine would be happier with around 540 to 580 cfm and some on other web pages suggest even going to 600 .. but that seems a stretch. The Demon street demon carb gets my attention in many ways.. it has the small primaries. but 625 is too much. I am looking into jetting it down and seeing what success rate is. but all these carbs save quick fuel seem to have fair share of negative comments. very confusing to a guy like me who gets caught up in a whilrlwind of details. they all seem to do the same thing. with an abundance of different results. Thanks for the input.

 

When it comes to a vacuum secondary 4 bbl carb, there really isn't anything as "too much" The engine is only going to use what it needs out of the secondaries, provided the secondary spring is tailored to the engine that the carb is sitting on. I've run a Holley 3310 750 cfm carb on a mild 302 build. It ran fine with the 750. Now all that aside, the throttle response with a 570 on that same engine was a little bit "crisper" with the smaller carb, but the engine was just as happy with the larger one. You mentioned "jetting it down", what gives you the idea that you'd even need to do that ? You cannot "jet down" the cfm rating. The carb's primary jets are what meters the fuel while the carb is into the main circuit, they in no way regulate the amount of cfms the engine draws through the main body. The secondary spring rate does regulate the cfms the engine gets by the varing spring tension as the vacuum in the throttle bores pulls against that spring. As for what ever "negative comments you've read on Holley or any other manufacturer, just keep in mind that feedback represents probably less than 1% of their sales. I've NEVER had problems with new or "little used" Holleys. Take the 3x2 setup on my 331, I bought the setup second hand. The carbs were 1 year old when I bought them. They've been on my 331 now for 11 years without ANYTHING going wrong. And sometimes they sit for a month between trips in the car the engine is in. When they sit that long I have to let the electric fuel pump reprime the fuel in the bowls before starting the engine. I do not use "off branded
gas in the car, it gets nothing but 91 conventional gas (less than 5% ethanol blend) and Chevron 10% ethanol 93 octane fuel, alternating between fillups. Run clean, quality fuel in a Holley and you'll have no problems. I've bought several used Holleys that were abused (dirty gas and never tuned to the engine) and simply opened them up to change the powervalve and/or the accelerator pump diaphrams and clean the bowls, then run them afterwards with zero issues. Most of what you've heard you can take with a grain of salt. Half of those comments wer made by people who never took the time to learn how a carb functions and never tuned them to the engine. I'll even go further to say, many of them never used a fuel filter either an fed it the cheapest gas they could find.