68 CST 396 - Need Advice

[story2tell]

I have been working on a 68 Custom Sport Truck, 396, 325 horse, TH-400, no AC, limited slip. The truck belongs to my Fateher-in-law and in the 17 years I've been in the family, the truck has not run right. I recently retired and have spent the last 2 months steadily working on it. The truck has an Edelbrock Performer RPM manifold and Edelbrock Thunder #1806, 650 cfm carb. We installed a mild Edelbrock cam, lifter and spring set. After fixing a bunch of electrical issues, the truck starts fine, idles fine and runs great up to about 3,000 rpm, then sputters and dies. The truck will start right back up most of the time afterwards and then does the same thing again. I have cleaned the carb, adjusted the floats, installed a fuel pressure regulater (set at 6 psi) to make sure it's not blowing fuel by the needle valves and flooding. The fuel pump is putting out 11 psi at idle and 10 psi up to 3,000 rpm. The distributor is a stock points distributor (new points, rotor, cap) with an adjustable vacuum advance which I have hooked to manifold vacuum. The truck makes 12 inches of vacuum at 800 RPM and 15 inches at 1,000 RPM. The vacuum module starts pulling vacuum at 7-8 inches and is all-in by 12 inches with 15 degrees of advance. The mechanical advance is free and working. Initial timing is 8 degrees BTDC and total timing is 42 degrees. In trouble shooting, I have changed coils and by-passed the ignition switch with the same "sputter and die" results. I've done everything I know to do and am totally baffled ...any suggestions appreciated!