Here is the configuration:

'76 Mav two door
302 V8, C4S tranny (New reman engine, used tranny)
Holley 80457S 4 barrel carb
MSD 6A Ignition, Billit Distributor, 8.5mm wires, Blaster 2 coil
Holley 80gpm pump (showing 7psi @ idle).

The problem...

The engine idles great! nice whine, 180 degrees on the thermostat, couldn't ask for more. Idle drops 120rpm in Drive or Reverse, but still idles smooth as glass.

But...

In drive, applying the gas very slowly will get me up to speed and everything is smooth but if from a standing start, or a slow roll, I apply anything other than the lightest pressure to the gas it start spitting and sputtering. An occasional backfire through the carb is not out of the question. (Popped off the Manifold vac plug I put on once). This will continue until I let out of the gas and allow the RPMs to come up slowly.

Bear in mind this is a brand-new engine, new exhaust, new ignition (all of it), new fuel pump, etc. The only thing NOT new is the tranny and it was working fine on my '73 Maverick donor.

I'm running 6 degrees BTDC on the timing at idle (no advance). I was running the (factory) rich setting on the carb but leaned it out a hair to get rid of some of the black (rich) soot from the exhaust (NO smoke). It did this both before and after the carb idle adjustment.

Any help here from the "old hands"? I'm about at wits-end trying to troubleshoot this one! Close to $10,000 in the Mav over the last 3 months and spitting and sputtering to show fer it!

Thanks in advance for any help!