Rob;
Pure stock has crossed my mind...still kicking around ideas.
John;
My car is a `67 Chevelle SS396...if I put a small block in it my friends would dis-own me lol.
If the tire/suspension rules were a little more liberal, I'd consider building an oval port motor, but with the skinny tires, I don't want something with an abundance of steam down low. Easier to get the car rolling on skinnies by moving the power upstairs and running steep gearing.
Essentially building a street race style car (albeit a nice one instead of the usual clapped-out sleeper), same ideas & technology applies. But I won't go into how I know those things.