[blue00gt]

I would go for an older Z car like some others suggested. You can put the 2.8L from a 280ZX in an older 240Z. I had one with dual webers, cam, header, hi-flow cat and catback, lightened flywheel, centerforce, close-ratio tranny from a 260, and a few other odds and ends and it moved pretty good for an N/A 6. I never ran it down the track but I'd say it was around a high-14 second car judging from some of my friends' cars that I raced. You can also get stroker kits to bump the 2.8L up to 3.1L.
Or if you want to be a bit more unique, I knew a guy at the local track here with a '63 Nova with the old carbureted straight six and he was running solid 13's on motor only! Don't know much about what it takes to build the power with those motors, but I know it can done.