318 1/8 time improvement

Agree with others above - fix the bog and get some good tires (note: tires, plural). Drag radials can be used daily but will wear out fast, best to get a set on spare wheels and use at the strip.
Also a bog costs a huge amount of time, at the most critical end of the track. Take your timeslip, and run it thru wallace with the 60ft improved by .150 . You will see what it might run.
Tune what you have before spending money throwing parts at it.