I get what you’re saying but from a practicality standpoint, the stated goal of 700 hp has to be easier and cheaper to accomplish with a 500” + BB. I get the OP has the good SB stuff already and changing to a BB is a PITA but that said, (IMO) the goal will be harder to reach and will be harder on parts staying with the SB. A 512” with decent heads and 2 1/4” headers you’ll be well over 700hp.
Bigger stroke might help the SB but can the resto block take a 4.100+ bore to take advantage of say a 4.25” arm? 450+ cubes could be in the ballpark for 700 N/A but you did originally ask about your current 410”. IMO that size is going to limit your output especially N/A.
This is a really heavy vehicle (5430!) with huge amounts of unsprung weight. (tires etc.) If he’s got 500 ft lbs. of torque at say 2,000 RPM as opposed to 600ft lbs. of torque @ 4,500 RPM it will get the truck moving faster.
Torque generally starts to fall off before peak hp so running it up to higher rpms for whatever amount of time might not be as useful as keeping it closer to the torque peak. It really depends on the application but peak torque makes more sense to me here vs. peak hp.
79Powerwagon, does the application need more top end hp more than peak torque? Where does higher RPM come into play?