Just was thinking of changing my Carb out. What would be a good CFM for a 1980 Chevy Camaro Z28 w/355 V8?

I believe the one I have needs a rebuild. So Just going to buy one and deal with that later. When you thump on the gas it just boggs.

I have a 625 Elderbrock on it right now. Was thinking Holley 725 cfm. But I'm not sure if that will work.

 

I mean 650 and 750 cfm.

 

I would go with the Holley 4160, which means you'll either get a 600 or a 750 depending on how your engine is built. If it's really mild I'd stay with the 600cfm, but if you've got a moderate to well built engine I'd go with the 750cfm. I'd lean toward the 600cfm for most 350 applications.
Vacuum secondaries will work much better for most street applications, and give not only better performance without that bog, but also better mileage when you're not getting into it hard.
The 4160 comes with dual inlets, so you need that fuel line and it also come manual or electric choke, depending on which you use now.

 

Well right now I have Elderbrock intake and headers. Looking to pickup some vortec heads this spring to give me more power. So do you think the Holley 600 cfm would do the trick?