carburetor for Ford 429 in L800

Ido not have a carb for this truck and have tried new Holley 650 vac sec. but did not run right looking for suggestions.

Define "did not run right".

The Holly 650 should be just fine on the ford 429 on the street.......Don

No it will probably not work as it is set up for a car engine . The jetting is wrong along with power valve and the acceleration pump.along with the lack of govenor. So what happened to the carb that was on it.

I've replaced the governed Holley carburetors on several trucks (Chev 366, Ford 361) with the 650 vac. sec. carburetor..............

Before you begin tuning the carb. the engine needs to be running 100%........good/even compression, ignition system checked out, etc.............otherwise your best efforts will be in vain............

You'll likely need to re-jet the mains(possibly a different plate for the secondaries as well)..........Install the highest value power valve(10.5 "/Hg) available(providing the engine is in good shape 15"/Hg vacumm @ idle or greater)..............also ,the spring for the vacumm secondary diaphram may have to be changed to a heavier spring other wise the secondaries may never open under load.........adjustments to the accelerator pump may be needed as well.............

If you can find some Holley literature(cross reference books) you may be able to see what comparitive engine/carburetor combos of your vintage were using for jetting, power valve, etc. to give you a baseline...................

It would be a good idea to get a tuning guide for Holley carburetors, it will prove invaluable.......

There WILL be some trial and error involved but it can be done............

I think you would be a lot better off with a carburetor that came on a 429 Ford big truck.

No power on low end, then runs better after 2200 rpm.

Contrary to what has been written, I believe you should bump up to a 700-750 cfm. I didn't have any luck with a 650 on a Ford 460, was always too lean regardless of what I did, and I finally got tired of changing parts. An out-of-the box 750 only required a couple of minor "tweaks".