So by your way of thinking, every rb26 with a ported head revving to 8000 is down on power, strap a t88 on the side and i assure you the results will be different, velocity is proportional to volume, not boost.
48hp seems a lot, how much power was it making, if a stocker was making 300hp at the treads, surely porting hte head didnt reduce this to 250?