Well I've asked about a good 2bbl carb before but the Clifford manifold is actually a 4bbl with a 2bbl adaptor and a Webber 2bbl on it when I bought this truck, I'm trying to figure out a good 4bbl carburator now that wouldn't drown the 300 6 banger, it has a header and true dual exhaust so should breath well on the exhaust side, I found a holly 390 cfm vacuum secondaries the I think might work but the thing cost $488 plus shipping! I can buy 750 holly's for less than that so I thought maybe one of you guys might have some advice, as far as I know the internals are stock in the engine.

 

I'm not a Holley fan, but in this case that's probably the best 4bbl for the application. With stock internals you aren't going to be winding the engine up much, so you won't have much air flow. That means you need a tiny carb if you are going to use a 4bbl, and that is the smallest one I know of.

But, why not run the Weber? Those are good carbs.

 

With a stock cam in there, 3600 is pretty much the end of the world. That Weber should do just fine.

 

I'd agree with the above. If you have a stock cam and a lack of headwork there's no real advantage to have a bigger carb. Aren't webers good carbs anyway?

I'm running one of those new 625 street demons. I bought it thinking the small primaries and many ways to tune it would be good on my rather built 300. I have an AFR meter and can't get it tuned well. It's never ran as good as the old vacuum secondary street demon it had on it before. I wouldn't recommend the street demons at least.

I think I'll be buying a summit 600cfm soon. Theyr'e praised by most people, have vacuum secondaries looks easy to tune, uses a lot of holley parts to tune, and shouldn't be too big for the 300.

My $0.02

 

I am not a fan of Weber carbs........I could never get them to run right.
I like Holley's, I know the Jeep guys run the v4 390 on the 258/six motor.


Now don't over look the Holley 2300 v2 in the 350 cfm size. It uses all the same "tuning" parts as the v4 carbs so parts are easy to find, not so with the Weber carb.
You will need a new adaptor the 2300 carb.


BTW the Holley 2300 has the base bolt pattern as the Motorcraft 2100 carbs everyone says is so great for the 300 six.
Dave ----