whats the best way to perfectly align a motor?
There's 3 different offset tools for your sled depending on which secondary you have:
1) standard button secondary, measure to the backside of the secondary
2) Team TSS-98 roller, measures to the front side of the secondary
3) Team TSS-04 LIGHTWEIGHT ROLLER, narrower than #2 above, also measures to the front side of the secondary
In addition to the offset alignment tool you may want a center to center tool, it's a little easier to check than measuring 11.5" but that's your call.
If your engine is slightly "crooked" meaning your offset tool touches the front of your secondary and the gap @ the rear of your secondary is more than the .040" +/- that they recommend, (and that .040" may be ZERO depending on whatever torque limiters/engine limiters you may have on your sled) here's what I did on my EDGE's:
I purchased an assortment of Chevrolet style starter shims @ the Auto Parts store, thickness ranges from 1/64" to 1/8". Install these behind the rear engine bracket to get it perfect.
Hope this helps