I installed a new Bosch # 00086 ignition coil today and it certainly seems to have eliminated the sputtering and backfiring upon hard acceleration. I tested the car for probably 20 miles today after the coil was installed. I drove it HARD and was unable to get it to sputter or backfire. It really responds to the demand for power now.

I will post an update hereon in a few days. I want to be absolutely sure the problem has been solved with the new coil before stating the same.