What will my 68 Dart 408 run in 1/4 mile?

I moved mine back. I took some half inch aluminum stock and made plates to go in between the front of the rear springs. I just bought longer grade 8 bolts to go through. There was easily a half inch to play with on the slip yoke. Well a picture is worth a thousand words, let me run out to the garage real quick...
IMG_20180615_071421.jpg