Now that's a Cam
 

Sorry moved to FE forum...

1Trk,
Just to give you a basis for comparison, here are my specs.
I have those heads in stageII configuration on an iron SO of 427 ci. We have the same trans and rear gears. The cam is solid and spec's; .613/.633 - 244/255 @.050 with 110deg. LDA. I have TWO 600's, [modified to 654 each] on a tunnel wedge. Timing is 14/24, in by 2500, vac is 7-8 inches @ 1000RPM. Like you, I have the ERA headers and stainless pipes.
You have 2.25" valves you're trying to feed with only 600 CFM. Plenty of velocity but no volume which is why it stumbles below 2500. You can probably benefit from a 950 at least, with those heads in stock form, have good driveability and a much better top than you feel now.
IMHO, keep the aggressive cam and add induction. You have a very deep breathing combo. A smaller cam will waste those high-flowing heads. You'll need less initial and then you can curve the advance correctly. I have freight-train power from 3500 to 7000, but it still drives nicely without fuss off idle. "Scary fast" is an accurate description as it's an 11 second set-up.
Best luck, and P.S. - Try to find out the CR from the Shelby guys. 10 or 10 1/2 would be good with the cam. Mike LeFevers was there when I bought my heads but is on his own now.
P.P.S. Your car's a beautiful color and best of luck. Mine is 20 yrs. old.;) ;)

Chas, agree I need way more carb to make that cam work. I don't have the stage II porting, just the stock on the heads. Also I have 10:1 compression. The holley I have on there now is a 750 vacuum secondary with the proform main body.. Supposedly flows ~800 CFM. The 600 was the edelbrock that I already removed.

Thanks on the color, love the car so far. Definately a well built car and it is fun to tinker on it.

So there I was, thinking, "I should replace that cam with something a little less radical". Took off the headers, jacked up the block, getting ready to pull the cam. Then it hit me,,, well while I'm in here. And thats why the engine is not sitting in my shop waiting for the new custom pistons, oil pan, etc. etc.

Sometimes you just gotta know WHERE to stop all ready! :D