[Steeveedee]

Alrighty then! Drop the head pipe off the exhaust manifold and try again. You may have a collapsed exhaust pipe or broken baffle in the muffler. It shouldn't go all the way to zero like that. Try it and let us know. I had a slagged converter on one of my cars and the vacuum didn't drop that fast. Yours isn't backfiring out the carb, so it's probably not a fuel problem. Also make sure that the heat riser valve is open.