Alex.....I have dealt with HOLLEY carbs for a few years (I have NOT touched a street aveger however).
Personaly I do not like Holley carbs..they have let me down in the past. Same goes for the Edelbrock carbs.
I like (they cost a little more) BG carbs.
BG has yet to let me down.
But if your carb is to do LIGHT DUTY ..... the holley will more then likley do just fine.
First off it's a 670 not a 650. 2nd I have a Holley Street Avenger 670cfm on my Corvette. I like it alot, the performance has been great, and it really was basically a bolt on and go thing. I happen to like Holley and have never had problems with them. I also have a Holley on my Camaro. The corvette is a show car so I don't mess around with it. I have a second Street Avenger, still in the box, here at home that I could probably get to you for less than what you would pay, if your interested. I work at a performance parts store so I get good deals. I bought the second one for my camaro but have decided just to garage it til next year before starting the restoration on it.