28's are too big. My Black Thunder has gone 78gps at 5300 with 26 Bravo 1's. I'm making 650hp+ so I wouldn't expect your boat to match but there is a lot of room for more speed with lower slip numbers. Cutting Edge Props advertises a larger dia. 4 blade prop for high x boats. Or try a 5 blade. Your higher x dim. will soften the blow to your outdrive.

Ok thanks I'll look into them, but for the cost of new big diameter props I could prob buy 1" spacers and use the 26's I have

Are you turning the props inwards or outwards? I'd try inwards if you havent yet. That may help pull the transom down, to give you a little more bow leverage(lift) with the high X. Just might get you to 70.

I'll give that a shot also, thanks! Seems to have plenty of bow lift as is but maybe spinning in will settle the stern in a bit ?

i thought turning props inboard gave stern lift, thats why normally seen on work boats.

Inwards gives bow lift. Think about it. When standing behind the boat, and looking at the rotation of the props....spinning the starboard counter clockwise, and port clockwise(turning in), it will want to pull the transom "down". Spinning them out, will lift the transom.