[fdbdw]

I would be willing to bet that most of the problems people have with any brand carb is not nowing how to properly tune them and dirty fuel. 40 year old tanks, fuel pick ups and fuel lines, microsopic dirt can easily make it through filters and rack your brain with issues so while your at it , get those things cleaned up. If you go Edelbrock , realize that fuel pressure is a biggie, you will either need a low presure pump or a fuel pressure regualator. If you have over 6 psi, it will never run right and you will leak fuel all over your new manifold. And if your considering the 600 performer or the 650 AVS, I would go with the 600. IMO the AVS is not worth the extra money.