He already personally goes to the guys who nail his rear bumper now and tell them nice job.
There are many things that can gain HP on a rebuild that would meet the rules, but not the intent. Like lightening pistons to the lightest single piston you can find out of many motors. Same with rods. Might need to deck the top of the block and maybe flatten out the head since the rebuildable ones were not ahem, straight enough, right? Thinner head gasket, etc... and you gain 10-20 hp with a 'stock' rebuilt motor. There were grand new motors getting rebuilt a few year ago in 10. Same with 6100 until some folks finally got sick of the cheating.