66 Dart going to the track!

My 72 340 Demon weighed 3500# w/ me in it, had an automatic and 3.23's. It ran 14.70's in good air (stock), using only 1st and 2nd (because of the 3.23's).
The BIGGEST improvement I found while looking to improve e.t. while it was stock, was valve spring pressure. It wouldn't rev high enough and after the shift would fall below the power curve. My buddy and I shimmed them up and the difference was amazing!
Your car has to be lighter, the power is probably similiar. I think you have a lot left in it.