Jimbob runs a 70hp Susi and IMO runs like silk, I havent used it myself enough to establish whether it has thisor not - however as jimbob runs it WOT 100% of the time I wouldnt know!!
Seriosuly, my 60hp Mariner on my 165 has this about 4500rpm, it doesnt vibrate as much but the engine pitch goes noticebly louder - a slight reduction either up or down cures it.
If it were me I would post on the World Sea Fishing Forum - a couple of the guys have 165's with 70hp susi's.
Failing this - go back to Warrior - it doesnt sound right to me.
Adam