Best 2 barrel HOLLEY carb for 1970 Bronco, 302

[Boccanegra]

I've been running a Holley 4412 2barrel (2300 series, with smaller jets for economy) since 1972 when I purchased the vehicle. I've been through 2 of those carbs ever since. Recently I had some sporadic issues that nobody could troubleshoot. The Holley tech strongly recommends the 7448 which is a 350 CFM carb, stating that my 4412 is basically intended for racing and high rpm uses. Since the 2 carbs are physically identical, I'd rather not switch to a different make. Does anyone have any thoughts about the 7448 vs the 4412? I only use the Bronco for city, freeway, and 4wd roads (sometimes higher elevations) but never for racing.

 

[phred]

The tech is correct. That is a much more friendly carb for the street. Frankly if you can find a good autolite 2100 you will be surprised just how well it will perform compared to the Holley. Nothing wrong with the Holley but IMO the 2100 is the best all around for a stock engine.

 

[73azbronco]

Find an auto light 2100 at a reputable carb rebuild place, done. Have them give you the jets for the highest altitude you will run

 

[Boccanegra]

Thanks to both of you. My problem is I have only 2 weeks to get everything in dependable shape before a very important workshop which requires my Bronco. I might just replace the gaskets above and below the carb body then look into a carburetor switch afterwards. I should point out that I have headers as well, always have (sometimes I wish I wasn't that ambitious when I was a kid!)

 

[Speedrdr]

Had a Holley on my 72. Not sure what model as my engine builder picked it out. It was a 600 CFM on an approximately 320HP engine. Every single time I ran it hard, carb needed adjusting on the next start up. Absolutely hated it. He ran Holleys on his race cars so he probably picked one that fi drag race needs.
This build I went with Edlebrock 1400 series 600 CFM. Like a whole lot better.

Randy

 

[Boccanegra]

Had a Holley on my 72. Not sure what model as my engine builder picked it out. It was a 600 CFM on an approximately 320HP engine. Every single time I ran it hard, carb needed adjusting on the next start up. Absolutely hated it. He ran Holleys on his race cars so he probably picked one that fi drag race needs.
This build I went with Edlebrock 1400 series 600 CFM. Like a whole lot better.

Randy

Interesting. So you went with a higher CFM?

 

[Speedrdr]

Interesting. So you went with a higher CFM?

Yep. So far it’s been playing nice and staying tuned. And I didn’t think to mention it, but the engine in the 77 is a 347 stroker motor at somewhere around 450 HP. Will dyno when it’s put back together. The engine builder did a dyno on an engine stand. Don’t know how much difference the numbers will be.

Randy

 

[73azbronco]

Google any reputable carb company bet you can get one inside a week.

 

[DirtDonk]

Unless your current carburetor has a real issue, I wouldn’t change anything, coming that close to some important event of yours.
If it runs now, run it.

I’m not familiar with the part numbers, but is one the 500 CFM and the other the 350 CFM? If so, I agree with the others that say either go with the 350, or go with the 2100.
Headers could possibly make a difference, but mostly in jetting, rather than what CFM the engine is requiring.
I could be wrong on that though, because 350 is pretty small. But when we tried them both, the 350 always ran better on the stock engines.

Remember that the Speedrdr is likely referring to a 600cfm four barrel.
Can’t compare CFM ratings to a two barrel.

 

[m_m70]

Unless your current carburetor has a real issue, I wouldn’t change anything, coming that close to some important event of yours.
If it runs now, run it.

Totally agree with this. OP didn't mention the issues other than "sporadic".

I might just replace the gaskets above and below the carb body then look into a carburetor switch afterwards

Quick, easy and cheap.....Would be the first thing I try.

I've been running a Holley 4412 2barrel (2300 series, with smaller jets for economy) since 1972 when I purchased the vehicle.

I'd stick with this carb. 2 carbs in over 50 years is a pretty good track record!

I've run the Holley 350cfm 2bbl and the 500cfm 2bbl and the 350 always ran better on my stock 302 with headers.

 

[nvrstuk]

The tech is correct. That is a much more friendly carb for the street. Frankly if you can find a good autolite 2100 you will be surprised just how well it will perform compared to the Holley. Nothing wrong with the Holley but IMO the 2100 is the best all around for a stock engine.

What phred & 73 azbronco said. DUMP the Holley, throttle linkage is easy to swap around

 

[nvrstuk]

Thanks to both of you. My problem is I have only 2 weeks to get everything in dependable shape before a very important workshop which requires my Bronco. I might just replace the gaskets above and below the carb body then look into a carburetor switch afterwards. I should point out that I have headers as well, always have (sometimes I wish I wasn't that ambitious when I was a kid!)

Yeah, just get it running till after your event. Ambitious stuff is what makes the Bronco yours!

Headers with free flowing ( I didn't say loud) exhaust and a good 4bbl intake & carb will noticeably bump your seat of the pants HP rating but more measureable than that is it bumps your rpm/mph range by a LOT. Example: my Dad's 302 in his stock '69 could turn up to 50mph in 2nd gear and it took quite a while to get there. I replaced his stock 2bbl carb & intake, exh manifolds and single exhaust with a 4bbl Edelbrock, 4 bbl alum intake, 1 1/2" dia primary headers and dual exhaust. I did exactly the same to my '68 earlier that year but I can't remember the actual numbers on mine as my Dad told his story over and over in the 16 yrs and 184,000 miles he owned it (ordered it from Ford).

On his way home he hit the throttle in 2nd and quickly got up over 70 mph and he couldn't believe it. Called me up and said I'd better not have killed his 14mpg that he always got. LOL Well, it didn't affect his mph as he drives very conservatively and he praised what the upgrades did for when he was towing and needed power.

Anyway, power can be a safety factor.

 

[Speedrdr]

Remember that the Speedrdr is likely referring to a 600cfm four barrel.
Can’t compare CFM ratings to a two barrel.

Correct, Paul! Didn’t even register with me that the 2100 is a 2bbl. Sorry for any confusion/misguidance. I swear I can read, just maybe not correctly interpret.

Randy