When putting the rings on the pistons, make sure the little "R" that is stamped by the nothch is facing UP!
Also, make sure the notch is around the pin in the piston when putting the cylinder on. If its not, you will break the ring. The cylinder should go on fairly easy. Do not force it - this usually means the ring is not properly aligned.
On the cylinders, criss-cross:
Front PTO Outside
Rear PTO Center
Front PTO Center
Rear PTO Outsie
Then do the MAG in the same sequence. Torgue to 20 ft lbs first, then finish at 42 - 44 ft lbs.
Those are the same torque specs I've always used without a problem. As far as a head pattern to tighten, in the past I've always just tightened one corner bolt then the opposite and so forth in a criss cross pattern as best as can be done.
This is actually partially wrong. You need to start in the center of the head and work your way out. It doesn't matter if you start in front or back, as long as you start in the center. I do the rear, center PTO (clutch) side bolt first, then criss-cross:
Rear Center PTO
Front Center MAG
Rear Center MAG
Front Center PTO
Rear Middle MAG
Front Middle PTO
Rear Middle PTO
Front Middle MAG
Rear Outside PTO
Front Outside MAG
Front Outside PTO
Rear Outside MAG
Do as mentioned though, tighten to 10-15 ft lbs first, then go back through to 22 - 25 ft lbs on the head.