Spark plug gap

Ok, guys finally made it to the track. Let me say very dissapointing. The car ran low 8's with my old set-up. My first pass 8.67. Bad 60' 1.97. Felt like a dog. Second pass 8.64 still a dog, just wanted to make sure it wasnt me. Running 34 degree timing so i backed it off 2 to make it 32. It ran 8.48. So I decided to re-jet. Took the fronts down from 75 to 73. Went to take the back bowl off and it was dry? Went ahead and put 81 jets in it had 85. Put back bowl on and checked the float and it seemed like it was right. Made a pass and another 8.47. checked the rear bowl and almost empty again? Im going to put the 700cfm back on it and see what it does. I'm hoping the carb is the problem, should have picked up not slowed down almost 1/2 second.