Can fuel pump be bad with a constant 5-6psi reading?

I thought about trying the test of disconnecting the vacuum advance and plugging it and then test driving. I don't think I've done it before. Someone earlier had suggested valves too tight, so I checked them the proper Chrysler way but there was none out of specs. I actually have another remanufactured Holley 1920 sitting in a box that I haven't put on because going through 3 remanufactured carbs and still the same symptoms I'm thinking that maybe the carb isn't the problem. I have not done a compression test on this one but I know I need to so I can see where the engine is at as far as being gone. I know when I had the timing cover off to change the gasket and front seal the timing chain didn't have any slack in it. I know they want the engine to be at operating temperature before you do the compression test but can you still do it without that so I can avoid getting burned. I've only done a test one time on another engine, don't you do one cylinder at a time? Or do I remove all the plugs at once? I recently had the intake and exhaust manifold off because of a small intake leak. Now the same place where the intake leak was before is no longer there. I cannot find any vacuum leaks around the intake or carb. I know the fuel pump isn't but about $20 but again it appears to be changed recently before I got the car and I don't really think it's the problem so I haven't changed it either. I wouldn't be surprised if the distributor vacuum advance is bad. So if I disconnect it and plug the ports on the advance and that is indeed the problem will the car be performing better or what is it going to do?