Slowly, but Surely
Hey Chrgr,
Ideal fuel ratio for a streeter is 14.7 pounds of fuel for each pound of air and we all know that, Right? I've read over and over that about 12.2/1 is close to ideal for max power.
I'd just keep jetting upward until you slow the car down, but you have to know that you have enough fuel pump. If the car's running out of fuel you'll not effect the topend mph no matter how it's jetted.
I had this problem several years ago.