I just bought a MINT Factory Custom 78' Dodge B-200 by Grand Systems. I am the second owner of this van. The first owner had it in a Garage for
25 yrs, and it has 63,000 original miles on the 400 big block. The first owner thought he had a 360 in it. # 1- When I brought the van home it had some hesitation. The first thing I did was a tune-up Wires,plugs,cap,and rotor. That didn't work. # 2-- I thought it maybe the Carb. It had a 2 BBl, so I replaced it with a Edelbrock Performer intake, and 650 4BBl carb. That didn't work. # 3-- Rechecked the timing. It was a little out, but not much. That didn't work. # 4-- Replaced all the vacume hoses. That didn't work. # 5-- Replaced the vac. controll unit. that didn't work. # 6-- Checked the vacume with a vac meter. It is fine. # 7-- Checked the carb float level. Fine. This is where I am at, STUCK !!Recap--- The van starts up fine. If I take it for a drive the van hesitates as you give it the gas. If you give it too much gas too fast it will back-fire. It drives fine on the highway. The motor dosen't smoke at all( just to let you know). Too me it sounds like a mild skip when at idling, but the Mopar guys at the weekly cruise night, said it sounds fine to them. They think it's the timing.I say a small vacume leak. I want to change the intake gasket again. What do you think??? I don't know what else to do.