I wouldn't dismiss Bills 500 Caddy suggestion out of hand. I seem to recall reading articles some years ago about them pushing 68/9 Chevells into 12 Second 1/4 mile times in stock form.

They don't like/need a lot of gear with 500 foot pound of torque they don't need it. You could potentially have a motor with very good street manners, able to cruse comfortably at hiway speeds and still meat your 1/8 time wishes.