Head Flow vs. Boost

Last year we ran some heads that flowed roughly 300cfm per chamber @750 lift on the intake. 408 sbf blown alky w/871 blower 9% od making 21lbs of boost. We ported the heads this year, they now flow 346 @750 lift, and we turned up the blower to 23% od, bored the block so it's now a 427 ci....we are running the same amount of boost, about 21lbs. I was told that porting the heads will make your boost go down, but are we getting any more air in the cylinders when it's showing the same amount of boost? I guess really i'm asking if we were to keep the blower the same as as last year (9% od) would we be making more horsepower with the heads flowing more even though boost would be down? I figured the boost is showing how much resistance you have in the chambers.
Josh

 

boost

Acouple things would affect boost. 19 more cubes will lower boost, larger runners will also. how many runs since restripping the blower?,if it has any.
the blower will slowdown producing boost as it wears the teflon.my .02

 

The blower is a mooneyham 871 tri-stripped, it was new in the first of last year. It probably has 20 passes on it? I haven't had it restripped yet....