All depends on how "tight" the engine is, those high volume oil pumps were meant for those quicky backyard re-ring jobs on the cheep where the bearing and lifter bore tolerances where at the high ends of their limits and the extra volume kept the oil pressure up while hot at idle or race engines with intentionally loose tolerances and big oil pans. If this is a proper rebuild where bearing clearances are within spec and everything is good and tight and you don't plan on spinning the thing up past 5500 rpm then a hv oil pump isn't the hot ticket. The hv oil pump puts more stress on the intermediate shaft especially on a tight engine running thick oil so like others have posted if you'r going to run the hv pump use the hardened shaft.