'78 D100-144K miles-original owner. Recently installed reworked head-lower end has good oil pressure and compression. Had starting problem after vehicle sat for a few days (vehicle sits most of time in the garage-has always been a fair weather truck). Purchase a supposedly rebuilt BBD and installed it-terrible hesitation from idle. Took carb apart and set up per specs-rebuilder had the balls mixed up with the smaller ball in the bottom of the accel pump housing. Cleaned and blew out all passages (so much for the rebuild) reset to fact specs. EGR disconnected, all vacuum ports except choke pulloff, cannister purge, vac adv to dist, and PCV valve working. Throttle shaft is tight in housing, unable to find any vacuum leaks while running. Idle adjustment screws about 2 turns out-idles ok, but still has a short hesitation when accelerating. Pulls strong and runs good after going through hesitation. Basic timing set to 12 BTC-notice timing mark moves 1-2 degrees (timing chain?). Looking for suggestions-this carb is better than the last one, and has cured the starting after sitting problem. Any ideas?

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Good gun control is hitting your target repeatedly

I would suggest raising the metering rods slightly. I always found the stock or rebuild positioning of the metering rods to be to low. Also play with your pump shot. You may need to give it more or possibly less accelerator pump shot. they are both very easy to adjust all you need is a screw driver.

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