I tried two dyno, both dynoject.
One from Mpower, got 160 whp with worn engine after tuned.
After overhaul, when to D4 racing, first run without tuning I got 165 whp. Which means i gain 5 hp after overhauling my engine, which is logical. Finally after tune on the second dyno, the results are 180 whp.
Also a myvi 1.5L got 80 whp, factory rating 102 hp at the D4 racing dynojet.
So i think dynojet is quite accurate at the least.
I think since your engine has cam profiling the dip is normal. That kinda power on a stock NA engine is pretty healthy. Looks like you did a good job overhauling. Whats next on the engine list?