What a (IC30A member) Chuck Erkman did when he repowered w/ a Beta -- may or may not be useful to y'all but I thought it was interesting.....
For simplicity I'll just quote him below
Ken
I repowered last year with a Beta-20. One of the tricks the dealer taught me greatly simplified the install & alignment. I made a simple "simulator" using 2" wide x 3/4" thick plywood screwed together in an "airplane" shape. The center stick was the total length of the engine/trans. The "wings" were long enough to correctly position your motor mounts. At the tranny end I added a piece of 2x4 that was sized to indicate the center of the prop shaft. Having measured the prop angle I was able to mount the motor mounts to the simulator and use it to position and pre-adjust the mounts to the correct height. Once everything was as close is I could get it I transferred the mounts to the motor and lifted everything in place. Once position I went through the alignment several times with a couple days in between to allow things to settle BEFORE I screwed the mounts in place. Once the mounts were screwed down I had to make some minor adjustments but I avoided having to relocate anything. I'll see if I can locate a picture of the setup but I killed the phone between then and now and may have lost the pic. If so I'll sketch something up. Good luck!