Snowman,

Take a good look at my picture album. This is a Holley 2300 2bbl 350 cfm carb. I tried to document my Hanger18 mod. The 500 cfm model is the exact same, just flows 150 more cfm. You might look at a 350 cfm model, I think it will be easier to tune than the 500. Both would work. I do believe that you can get a Holley 2300 2bbl for much cheaper than a 390cfm 4bbl. I would sell it and find a 500 or 350 cfm 2bbl. Just my .02c.

https://picasaweb.google.com/shadmeier/JEDTurboHuffer

Boucher