Bob's nose cone = not a good choice?

[croSSed]

I just sunk $1000 + into a beautiful Bob's nose cone, and I'm disappointed. Here's where I was, and where I'm at.
Where I was:
2.4 175 on a 17' Cee Bee Avenger Mach II, all solid mounts, Sea Star hydraulic steering, stock 2:1 lower with the top three holes plugged, jack plate up as high as it would go before sucking air, 28P big ear Chopper, 78 mph at 6400 rpm, about 8% slip.
Now, same rig, same prop:
2:1 coned by Bob's, was able to get the jack plate up about another inch (see pics). 72+ mph, 6600 rpm, about 18% slip.
Not what I was hoping for. I have a couple options I think: Buy some set-back plates to mount the motor higher on the jack plate (there's no way now to get the plate or motor any higher; they are both as high as they can go) to take advantage of the LWPU and scrub drag from the extended lower. MAYBE I can reclaim the speed I did have. The other option I have is to swap the nose coned lower for a spare stock 1.87 lower to see how that performs with the chopper. I do not like the idea of adding set back plates to the jack plate as I'd be adding more weight to the transom, and giving more leverage to the motor against the transom, which is already a little stressed. There are some slight stress cracks in the gelcoat at the transom that started to appear after installing the jack plate. One of the other things I'm thinking is the 2:1 lower is now coned. It's permanent. If I don't like the way the 1.87 lower performs with the Chopper, as in, I'm getting something less than 78 mph, I could have all the gears swapped out. Turn the Bob's lower into a 1.87, and the stock one into a 2:1. Then, sell the 1.87 lower. I'm calling Bob's tomorrow (Monday) to get their thoughts.
I would appreciate your thoughts. Thank you.

Sorry about the upside down pics. This site just will not let me post pics properly. They are oriented the correct way on my computer, but they won't post properly here. I even tried turning the original pics upside down to see if they'd post correctly. They would still post here upside down.