Tom you had pretty much four problems with the 150s, the floats were off, one carb had a problem that would not allow the mixture to be adjusted, the fuel pressure was a little low and the number one issue was the intake gasket leaking.
The new version of intake/exhaust gasket is a problem, I know of at least three people who have used them and they all have vacuum leaks. On Tom's car I tried two not counting the one on the car when I got it and they were all the same, leaked like a rusty bucket. This gasket is a black material with a shiney metal side bonded to it with a bunch of little holes stamped in the metal that I guess are meant to stick the metal to the gasket material. I finally gave up on the gasket and made one out of header gasket and sprayed it with K and W copper coat.
150s are not difficult to adjust is a little easier to learn if you have someone show you. I typically back the mixture screws out 3 and 1/2 turns making sure both are out equal amount [book says 2 and a quarter I think, can never get one to run right with the screws out that little], get the car running and then adjust the balance, with a uni syn of some sort, the rubber hose thing just forget it the only thing a rubber hose is good for is to smack yourself with for getting in this position in the first place. So once balanced I tinker with the mix for best RPM then check the balance again, lock the slip joint for the throttle back down then check the balance again, maybe make some minor adjust to the balance with the carbs locked together especially if the shafts are worn. But to get the thing right it has to be sealed up no vacuum leaks, you may also want to do a valve adjust , check the timing and points if you have them, then check your balance and mixture again cause if the valves are off it will not suck and blow the same and you could have to tinker with it some more. Ther is other stuff, centralize the jets, float level get the mixture screws to zero on each carb before backing them out 3 1/2 flats but over all it is not real hard to figure out unless you have a base problem like a vacuum leak or very low compression in one cylinder, burnt valve that sort of thing and the carbs will tell you something is up because the car will simply not run right or respond to adjustments, and if you have to have the choke out to idle it is a pretty good clue things are not all they should be.
I really like the Strombergs they give very nice throttle responce, no holes or bog and with a just decent motor you can pull down 30 mpg.
