Curious as to why you wouldn't want to stay with the small block?
I actually kept the stock stroke on the 340 to make sure it didn't melt the tires off 24/7 driving around on the street. It still makes 400 lb-ft at 2800 rpm. If it was me, I'd spend my money on a fuel injection kit and a roller cam over a stroker kit. An over 450hp street car has a hard time hooking up without traction control. I can stab it at 20 mph and blow them off, and a nice healthy bark on the 1-2 shift (4-speed) at 55 mph. I need to do the suspension and install the 275-35-18's I'm planning on to replace the 225-60-15's.
My Friend was looking into vintage racing for a 64-66 Cuda or Dart. Most of them even allow you to use 318's...one had a 100 lb weight penalty, but it's probably still worth it.