Lotsa oil up there..??
No discoloration on the cam at all..??
The reason I ask is that a common problem that pops up is plugged oil passages with these 750s..
Then the top end gets dry and the cam seizes to the towers...
If it all looks good.. and.. all is as I've outlined above.. I think your next move is to tear the motor down..
Theres others on here that can add some good advice with this..
Give it a little time here and see who else posts any ideas..

Build it the way you want it ..... then learn how to ride it like you own it..
www.lowridersbysummers.com