Worked on the LeMans this weekend
 

When I got this Le Mans I only paid $300 and you can see it in another thread. It had a bad Holley carb on it that the PO had messed up. It was a 600 and was not good for the car anyway. So I found a completely rebuilt (new shaft bushings, replated, etc.) for $180, its a Carter 500 cfm electric choke.
After installing it, it still ran poor, was only running on 4 cylinders. I had already ordered a new HEI for it, but wanted it to run now. I checked everything and the PO had replaced everything with new (cap, points, rotor, plugs, wires, etc.) and it still ran bad. Cylinders 1, 5, 7, and 2 were not firing.
I went back to basics and got out my old dwell meter and timing light. Dwell was off so I got an allen wrench and started turning it. It came alive! all 8 started hitting in perfect harmony. A few more tweaks and it is running sweet.
I can't believe how well it runs with the right carb matched to the engine size and everything hitting like it should.
After a huge smokey burnout I took it for a drive, nice car. I love this thing.
I know the HEI will only make it better, but I love it already.

That is awsome. Need some of those smoke show pics.

I always liked the points ignition when I was racing my GTO up north. Correct point settings on these cars can make a ton of difference as will correct timing and advance. Myself I feel your still small on the carb but you can upgrade to a good Q-jet at a later time. Until I get the Q-jet set up right for my 350 I'm presently running an 800 Holley spreadbore, yes it's a little much but drives really well.

I do like the way it runs now, but I already ordered the HEI. My son will be driving this and I don't want to have to worry about keeping them set.
As for the carb, I looked at three different calculators and all said that 500 CFM was correct for a stock 350.
The guy I got it from had a 600 Holley on it and he said it got real bad mpg and did not perform that great. With the 500 it performs great, no bog, all go.

Bigger is not necessarily better.

George