I heard a lil ol "wives tail" that a vacume secondary carb gets slightly better feul milage than a manual secondary carb. Is there any truth to this? I could see it maybey, if you have an overdrive unit behind an auto? But still, I don't know.

 

Vacuum secondary for an auto trans and heavy vehicle.
Double pumper for a light car, high stall converter ot manual trans.
These rules apply to Holley/Demon carbs.

All Edelbrock carbs are mechanical secondaries with a vacuum controlled air flap on top.
These seem to give the best mileage with good performance.

 

So your saying the Edelbrock is overall the most efficient on a Daily driven vehicle, I just heard they are easyer to work with too.

 

Yes and yes. I have one that ran great on my 460. I sold the truck and kept the carb, (put a 600 Holley on the 460) and it runs just as well on my 351W now.

Depending on the engine size, I would go with a 600cfm Edelbrock.

 

Thanks, I was told I need between 800 -850 cfm by my engine builder for the hopped up 460 I had them build. Supposed to be around 600hp. Edelbrock makes an 800cfm carb, so I guess I'm good to go!

 

I have a 750. This is the carb I mentioned earlier.

I would suggest the Edelbrock 800cfm AVS Thunder carb for your application.