Snowman,
If you want to try another carb, then send me a PM and I'll send you one. I have my original monojet, rebuilt, that worked great before we began our build (you can buy it, try it, or send it back depending on how it works out).
Removing the head is a great idea if you have the time and the money to go over the head. But if you are concerned about a mechanical internal component issue, then I would recommend a compression test and cylinder leakage test when the engine is cold and again when the engine is hot. The tests are cheaper than head work (especially if all of your problem is either fuel delivery or ignition related.)
Good luck
p.s. - think HEI
