Long time no post... All righty. On my little 307 mouse, I've got some 1.95/1.5 valve 58cc heads. I port matched em' to my edelbrock performer intake. I am running headers with 2" exhaust. I am currently running a holley 650cfm, but I think it's way too much carb for this little 307. When I hit 3500RPM's it just stops pulling. It also feels like there is little torque until 2000 RPMS. I can turn the idler screws all the way in and still run just fine. I downjetted the carb a few years back by 2 points in the primary and secondaries. I am wondering if I should go with a carter or edelbrock 500cfm or 550cfm. Please help me breathe some power into my green machine!

Sounds to me like you've got more than one issue, but if the carb is set up right it should run ok, even if it is more carb than you need. I'd do a few things:
Check float level
Check/Replace your power valve(s)
Watch the carb while running - is gas dripping into the carb?
Really, I'd try to get the carb back to factory specs but keep the jets you have in there now.
Other considerations: discharge nozzle size, secondary spring if vacuum operated, fuel pressure.

A quick way to see if it's too rich is to pull one of the manifold or base of carb vacuum lines off - it will let more air into engine without letting in more gas.

What area of Chicago are you in?

Float level and power valves are okay. I have adjusted the idler screws to set for most vacume. I turned them all the way in then backed them off 1 1/4 turns. There isn't any fuel dripping into the carb. Also, one more note. Ever since popping on the new heads and cam which is a Comp Cams xe262 grind. I have had to retard the timing by 6-8 degrees or it wants to die. My compression is around 9.6:1 I am running 93 octane. I believe the cam around .461" intake and .463" exhaust. It just seems like it's getting too much air. I have also added a pertronix ignitor II module and increased the gap on the plugs to .38 from stock .35. I don't have any vacume leaks. I am pulling around 13-14hg on the guage.

I ran a Holley 600cfm 1850 series carb. on my stock 307 years ago. Ran great. Had the Performer manifold like you as well. Besides the carb and intake, the motor was completely stock and had dual exhaust added.

Try those tips Xtreme gave you though.

Now that I am thinking about it... I changed the jets long ago, when I had the stock heads and an Edelbrock performer cam that was something like .430" lift. The stock heads were 1.7 intake and 1.4 exhaust. My new heads have fairly larger valves. Could I possibly not be getting enough fuel? I am pretty sure the stock jets were stamped 65. The Jets I put in were either 62 or 63. I am running the original fuel pump. Should I consider a new pump? Rejet the carb back to original 65?

Pull a plug and see what it looks like. It sounds like you are running out of fuel, but it also sounds like you're getting too much fuel at idle based on your original comment that it runs with the screws all the way in.

Assuming it's lean, the problem should get worse if you leave a vacuum hose unplugged, but it might not be easy to notice. If you don't mind opening the carb, putting larger jets in (try primaries only first) and then cruising in it you should notice a difference. I'd go up minimum 2 jet sizes at a time. No need to run it above 3500 rpm's, if it's lean you don't want to do that for long. It's important to only make one change at a time and then check out the results so you know if you're headed in the right direction.

Thanks, I will try it out as soon as the baby comes out of storage. I have been putting together a plan of attack. I am just waiting for this weather to get better.

At least the salt's been washed away....

Good luck!

a nice Q-jet