whats the difference between a2005 & 2006 5.9L .Does the 2006 have stricter emissions.Which one would you choose

 

Emissions are the same. Only real difference is PCM on '06 built June and later as they went to CanBus.

I've also heard that some very early '05 did not receive wastegate turbo although I can't verify this. Every '05 I've seen had it as well as all '04.5s I've seen.

In my opinion go for the best deal on the truck in better shape...