I'm running a bone stock 292 with an 600 edel, clifford intake, headers, and hei currently. Haven't flooded the thing out yet. Pulled a hill the other day in 4th with it at 1/2 throttle...no bog...accelerated like a dream. BUT, my truck is only around 4000 pounds compared to a 4x4 C20 which I'm sure adds another easy 1000 pounds which will have an effect. 600 cfm edels have been run several times on 283's and 305's. A hopped up 292 will enjoy a 600 believe me. No jet down needed or anything like that. Larry at T6 put a 600 on a bone stock 250...talk about overkill but it ran fine. Now....my hopped up 292 will be running either a 600 edel or a 625 demond...haven't decided yet. I didn't go with a crazy lumpy cam either. Specs are: 268H duration. 219 @ .050 .486 lift on a 110 lobe center. Will be lopier than stock for sure but not like a BBC. I made this engine more for "driver rpm" torque...this engine will peak torque around 3500 rpm and horse power at 5500(little low I believe), with that and my tko600 it'll be an optimum cruiser but will still embarrass a 350/290. lol So its really all in how you build the thing. The 292 in my 66 I drive like a stolen truck....love making that old beat up 6 scream. With the 600 I mainly noticed...little better acceleration(especially pulling hills), and more top end power....the headers help with that to. So your 600 will be fine...especially if its fine on my stock 292. The 500 was considered more of the "if your concerned about mileage" carb. lol And if you really are then put a 500 quadra jet on there.
EDIT: speaking of chevy script valve covers...here's how I painted mine on my 66's 292.