Big Block Carb Question

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mda440

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Hi all, need some carb advice. I'm hoping the 451 will be finished in a month or two and need some advice on a carb for it. HEre's the situation: my dad's 340 swinger had a 750 AFB COMP SERIES carb when he bought it (way too big), and of course it smoked a bit, likely washing down the cylinder walls. Since then he's put on a 625 I think and its great. Anyways the 750 is sitting there, was just professionally rebuiltand is ready to go and available to me. I know a Holley would make more power, but is this carb worth a try? Should I just install it and break in the engine and drive it, is it big enough, and is it possible that the jetting could be off enough to have a meltdown. Just wondering opinions - I don't have much carb experience as I only work with fuel injection at work. Thanks for any help. Oh yeah, this motor won't see anything over 6000 as it's built mainly for torque, so I thought 750 may be ok???
 
The carb, by way of cfm rating, is enuff for the engine in most cases. And most certainly worth a try. I have one like you have on the shelf. I used it on my 360. It is a good carb. However, they don't really like big cams/lots of overlap. The Holley can be tuned better for that.
If you need a jet and rod kit, purchase one Edelbrock kit from Jegs/summit. Also a air fuel ratio gauge and O2 sensor to help you tune it up. We would need to know about the 451 build to recomend a cfm rating.
A word on carbs that I have noted, is Holleys make more top end HP while the Cartes seem to better in the down low torque department.
Don't short change the Carter for performance. All out race is another story.

Also, if it's lean on start up, you can swap rear jets to richen it or in a worst case, leave out the rods. It'll run WAY rich if you do that.
 
Thanks for the reply: Heres the build, 451, eddy 84cc heads, hyd cam 238/246@ .050, 480/.495. ross flattops, 10.2:1. Using dual plane eddy manifold.
 
It'll work well. You could use more cfm. The HP difference would be small, but there.
Try a few tricks to the Carter first if you wish. K&N stub stack and extreme lid with a 4 inch filter if you have room. The stub stack is the only thing you can not reuse if you change carbs. The others are a win win.
The carb itself can have the boosters removed and whittled down to create more flow since there will be less restriction and more open area. Becareful when messing with the boosters, new one are not avalble. (sp) You'll need to pirate a Edel. AFB for boosters.
 
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