Carb Choice? It's different than the rest, no really!


Active member
Well, only a little different.

I have a couple of 1.21 2150's and was planning on rebuilding one for my Offy C/HD manifold swap. However, I found an older Holley 2300 in my carb pile and it lists as a 275cfm off a late 60s IH 266 V8. So now I'm not sure which to try? Any thoughts?


Active member
Think the 1.21 is too much for a stock engine? They're about 350cfm if i remember right. At 350cfm, I feel like a holley 390cfm 4bbl would deliver comparable power and better mileage?


Active member
I think I'll take your advice and just rebuild them both. If nothing else, it'll be a fun experiment. Out of curiosity, have you ever swapped a 2150 to a manual choke? I've got one set up on my carter and like the simplicity.


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I have used a manual choke. I like them because I live out a ways from anything and generally it is a couple mile highway drive to anything. Once the car is started and on its way I could push the choke all the way in and all is well.
If you have to do a lot of stop-and-go during warm-up an auto choke, properly adjusted, is better as the engine slowly comes up to operating temperature.


Famous Member
You will love rebuilding & working on your 2150, they are the easiest carb to work on that I have ever messed with. Being able to remove the top plate with the carb on the car/truck to make needle/seat & jet changes is a big plus. I think your mileage will be better with the 2150 0ver the early Holley as the 2100/2150 use smaller jets sizes than the Holley (any where from 8-10 sizes smaller). My Holley 2300 350cfm has factory 62 jets & my 2100 has 48's.