David, its not just boost pressure here. If he is running pump, he can hit a boost number o 7-8 relatively easy.
Bu yo can't compare his deal with yours for a couple of reasons. If this is a lake/rier deal, it will be a slug anytime its not in boost. You could care less, your never running it at anythig less than hammered. You are at full boost from the hit. Also, your running alky. Think about the amount of fuel you have in the port along with the air. As far as the air is concerned, the port shrank by that amount. and its more than you might think. FC Pilot has a post in Info's air flow and a butt load of boost. But Funny heads are HUGE, and only spin 8500 and are boost limited. It because of the amount of fuel in the Funny's port. I also wonder what he redline of your deal is compared to what the OP i willing to spin his.
There really isn't enough info here to make a call. But it has a cam like a race motor, he has been recommented heads for a race motor. You can assume alot from the post, dry headers(hopefully) v-drive, properly geared and prop.
But like Big Steve said, whats the usage, is it a race motor, or is it a lake/river deal on pump? is it inner cooled? carb size?
Comparing your drag deal to a river boat, unless strictly for banzi runs, somewhat misses the mark.
If its a race deal, he needs more compression, or more blower. He would, as you said, have to spin 25%+ over. More like 30 on a unstripped stage 1 BDS. Thats a little faster than I would care to spin a gas blower, specially if it isn't inner cooled. And if it is, he just sped the blower up another 2-5% to get the boost back.
the whole deal needs why more info.