Looking for some racing advice.

[Verne_Frantz]

Darren, The single and simplest inprovment you could make for now is tires (slicks). A 105mph should be turning about 13.2 with decent traction. My prediction is that if you use slicks and reach a 13.2, you're mph will be 106.
After that, it's time to change the rear gears. A 105mph the way it is, and the way you're driving it, means the 12s are easily in reach. (but you'll have to gear it so you're using <u>all</u> of the motor)