420ci is impressive becasue thats an awefull long stroke to get there! lol Play it the other way, why not put a LR4 crank in it and knock it down to 311ci? If ya still stick some baller ass pistons & rods in it to take the abuse, why not just put a bigger jet in the plates to make up for the displacment difference.
thus taking some of the CI argument relivance away.
Its aparant the car has the DL and the setup to plant the power and hit a goal. Thats the impressive part IMO. My point is its just not mind blowing to me just becasue its +/- 50ci or something.