Racing Beats
full Peripheral Port Turbo's are around that same ~270bhp level btw. But to attain that you need a full open exhaust! not practical even on race tracks. I listed a few of partial pp's in the first post, worst or just a bit over compared to RR street port. so you can see there is not much in it really at end of the day once you have a decent street ported motor.
There is a big gain from small stock ports, but how much power do you want
190 odd bhp level to 240bhp~!