If you are serious about weight, don't relocate the battery to the trunk. All that big copper cable isn't light. Buy a small gel cell battery (13lbs) and make a lightweight tray and hold down out of aluminum. Keep it under the hood and cable lengths short. With the small gear reduction starters, there is no problem starting a 11.2: 1 compression small block.
If you are thinking about running drag radials, definitely go with the smallest tire you can get away with. The MT 235 Drag radials weigh 28 LBS. The 275 weighs 33 LSB each. Rotational weight is worth 10x static weight.
33 - 28 = 5 LBS x2 tires= 10 LBS x10 (rotational) = 100 equivalent pounds which should net .10 reduction in ET.
My best 60ft on the MT 235 drag radial is 1.56 in a car putting down only 300 HP to the rear wheels.