You don't need a 305 on the car, just do some EVO wheels with the M&H 26x8x17 slicks. All the traction I could handle at 500+ WHP.
Bigger tire = more drag and unsprung weight.
I'll sell you my slicks for $200 shipped if you want to try them out, pick up some EVO wheels for cheap locally, they're 17x8 and bolt right up.