i wouldnt get so wrapped up with dyno numbers, after all, they are just numbers. they can also be manipulated to say whatever you want them to say..
i personally would not build a supercub motor. if you do, i definitely would not build the 10mm super cub. the intakes are too small for the amount of air needed to run the motor efficiently. if youre dead set on a super cub, go with the 4mm..
however, i would seriously consider just building the 10mm cub and be done with it. it will make 100hp easy on gas even. the 4mm cub can make big power numbers, but you will need to look into outframe pipes and alcohol.
ive had both the 4mm and 10mm cub. the power increase on the 10mm is very noticeable. ive never had it dynoed and dont need to. the difference is there. ive been racing against a 10mm supercub for the last couple race seasons and im not impressed with it. me with my 10mm cub and my brother with his 4mm cub consistently beat up on it.