Nice looking ride
@Dmopower. Your mileage and power build isn't everyone's cup of tea, but it is right up my alley.
I took a different approach back in 1994 I put a 518 in my 340 challenger. It would knock down 20mpg on the highway provided I kept my foot out of it.
There are some good threads on moparts you would be interested in. Look for super duper 318 and super duper 5.9 threads by
@hotroddave. Not sure if he is on Abodies or not.