Got the new Mickey Thompson ET street R tires 275/50 15's mounted. They fit under the fender skirts. Should get me to 11.99. If you look close in the pic you can see the old M&H drag radial 275/60's under it.
You will go 11’s easy with some lite aluminum drag wheels. Those steel wheels are near 30lbs each.
What rear gear ratio do you have?
How are shorter tires going to pick you up .279 of ET?
3.23 ratio, the 275/50's are ~2" shorter. Its not just the tires, i installed an O2 sensor bung so i can jet the overly rich quickfuel carb, and lean it our a bit. I am hoping the shorter tire and properly jetted carb will pull off a 11.99