Besides vacuum leaks what are causes of low vacuum at the intake. The truck runs fine but will not idle unless the choke is on. I don't think it is pulling enough vacuum to get the gas up when the choke isn't on. I'm dealing with an updraft carb. I'm on my third carb, the first two were used and rebuilt by me. The last was NOS. Problem still exists. No vacuum leaks.
I'm going to test it tomorrow, it's to late tonight.
