I still have the compression and I had the same thing when #2 had 25lbs of compression. I fixed the head and thought 'wow it will sure help the carb to have good vacuum. The other lines I have pulled have good vacuum and none pulse except that one. In the garage the engine is smooth as can be and revs nicely but after a 1/2 mile of driving it starts acting like its running out of fuel and then it will start to run fine for a bit and then back to gagging and choking. I know its a major carb issue but I would like to know about that one single line before I jump on the carb.

Is it supposed to have a good strong vacuum signal like manifold vacuum should be?

On the end of the box there are two lines there that one has good vacuum at idle and the other must be port vacuum because it is rather weak.