Thanks Dan. After speaking w/Trey it appears I need to raise the jib a little further on the forestay to get the right angle. I have 12" of adjustment available there. Will have to secure the jib to the chainplate and forestay with line since the cleat will not reach the chainplate with the sail higher.
Dan, I had allready considered the movement of the unit. Mine is off a I-20 so its a little different attachment style. With the legs cut down and machined it will be able to pivot up and down in relation to the crossbar.
The sheet angle was my main concern and I think Trey is right about raising the jib, I believe the tiger runs longer bridles than the 18 which would force the sail to ride higher on a tiger than on my 18. That might be all there is to it.
BTW I do have a tiger jib!