Rebuilt 350 (357) bogging down issue

[str8edgec10]

Need some help guys. Motor has approx 200 miles on it. Followed break in procedure, distilled water, breakin additive, 20 minute roughly 2500 rpm etc. (Mild cam) Anyway, ran perfect until on the way home from a local car show. In which I won the class for "under construction". (Diffrent story) basically truck idles ok, when I try to speed up it bogs down almost like its starving for fuel. At around 40 mph it quits doing it and runs perfect. I must admit it has a clear plastic fuel filter between fuel pump and carb. (Will be putting a metal one) I noticed at idle that it is about 90% full with bubbles jumping around and looks very sporatic. (It didnt do this prior to the bogging down issue. Boiling fuel or vapor lock? Bad sock in the tank, collapsing fuel line? Oh yeah, it only has drivers side tank. Also, has 91 serp setup with proper reverse pump, etc. Edelbrock 650 manual choke in cab.