Hi James,
Welcome to the ICS Forum.
We went to Sky-Tec in 2003-ish for the same reason you are changing. PA39-10 is very happy with them.
The NL I think is the newest model and includes an on board spare shear pin - haven't had to use it but its there.
Hope this helps - there website is
http://www.skytecair.com/Lycoming.htmThey advertise in the Flyer and donated a starter to last year's convention - which ironically, we won and just sold our older Sky-Tec to another twin owner on this forum.
Hope this helps.