holley question...

yodabiri

Well-known member
I just went to a swap meet in Turlock, CA and i saw a bunch of holley 2bbl carbs there! And i was considering buying a used holley to put onto my mustang's 200 in the near future, but i realised that i have no clue how to tell a 500cfm from a 350 cfm carb...(haha please excuse my ignorance i am a novice and still learning!) Can the good people at this forum help me out please!

Thank you in advance!
 
The number to read is on the choke horn right side.
I dont know the number of the 350 cfm carb
500 Cfm is "List -4412"
I am sure someone on here knows the 350 cfm number
 
The 7448 is the 350 & the 4412 is the 500 carb.

I would use the 350 on a mild engine, & the 500 on a well modified engine with higher compression, camshaft & headers.

I have used both & the 350 is the more friendly carb for just general street driving even with a modified engine.

The 350 runs great with a 60 jet, while the 500 likes the 68 jet, but with a .010 wire restriction in the power valve restriction channel.

All test were run using an inovate LM-1 air fuel ratio tester. William
 
Thank you very much...i knew the identification had to do with those #'s but i forgot which were which...

Thanks!
 
I have a question about the holley swap...
if i switch to the holley i will have to ditch the loadodizzy..right? And replace that with probably a duraspark. I am not that good with electrical things (in fact i am really bad with electrics) anyways i was just wondering which i should do first, the dizzy swap or the carb swap? I was thinking the dizzy swap...but i may be wrong. And if i want to do the dizzy swap would a normal mechanic know how to do this swap and not mess everything up? (I know its a weird question but i had to ask)
 
There are some Economaster versions stamped List 9117 on the choke horn. They have a funny 8 slot 'turbine' style venturi booster which looks very interesting!

They are actually more like 320 cfm, but the same size as the 350 cfm 7448.

Oh, just to amend the above post, the 500 cfm carb is the List 4412. The 350 cfm carb is List 7448.

But hey, I won't hen peak someone for getting the numbers da wrong way awound! Anyone who is nice enough to hand out the inforamtion desserves a handshake, its what makes the site so much fun!


Really rare is the List 6425, a 650 cfm Holley with Dominator style crome air horns reaching for the sky. These have 62.5 thou over throttles and venturis for 1.75" throttles. Great carb for a really hot in -liner!


The easiest way appart from the list numbers is to look at the throttles and carry and carry a rule. You'd be supprised how many carbs have been fiddled with. Yu can fit all sorts of 500 baseplates to the 350 , or mix and match some of the 280 cfm stuff from the AMC 232 and 327 V8's.

If its 1.6875", its the 500. If its 1.5, its the 350.

Old Internationals and AMC Rambler variants used an early version of the 350 with even smaller throttles.

The 280/320/350/500/650 carb is called the 2300 seires, and for the I6, its the best carb for the money anywhere!
 
I'd beware of some 350s that may have 'reverse-idle' metering block. That can be identified at the idle mixture screws, where there is a chrome sticker around it and it says "LEAN" with an arrow counter-clockwise.

The stickers may have gone long time ago, but if it has not been cleaned you may see some evidence that the sticker was there.

On a modified engine you'll soon find a reverse-idle model to run out of fuel at idle and low vacuum conditions unless some "tuning" is addressed or way too big jets used.
 
yodabiri":ubwqdcpn said:
I have a question about the holley swap...
if i switch to the holley i will have to ditch the loadodizzy..right? And replace that with probably a duraspark. I am not that good with electrical things (in fact i am really bad with electrics) anyways i was just wondering which i should do first, the dizzy swap or the carb swap? I was thinking the dizzy swap...but i may be wrong. And if i want to do the dizzy swap would a normal mechanic know how to do this swap and not mess everything up? (I know its a weird question but i had to ask)

You will need to do a dizzy swap, but if you dont want to do a duraspark swap, you can swap in a 67 or later dizzy. They have mechanical and vacuum advance.

Later,

Doug
 
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