408 Build!!!!

I want to build a 408 for my 86 dodge, I want it to be more of a stump puller than a screamer though. I also want to be some were around 11-13 mpg with 400hp. I was going to go with a 670sa holley and either the eddi performer or the rpm not sure yet. For heads i was looking at some RHS X heads with 1.92 or 2.02 valves from hughes.

I have a set of mopar 1.5 roller rockers that would be sweet with a roller cam but there very spendy and Idk how hard it is to convert from a flat hyd to a roller hyd? Either way I'd like to get a cam with a healthy idle but good torque. I was going to go with summits cast scat stroker kit W/ I beam rods and forged dished pistons. I dont plan on F.I. in the future so I think cast w/I beams would be safe to 450 hp at 6,500 but I dont plan to wring it past 6k. Should I bolt or stud the caps and heads? Whats the advantage of the two?

I guess I just want some opinions and prefrences with building a 4x4 408 with affordable everyday economy and still put chebys and lil annoying rice burners in there place.