I need opinions on which way to go with my truck.

My truck is a 2000 NBS eclb silverado 2500 with the 6.0L (lq4) and a 4l80.I have 9 inches of lift,38.5's,ranchhands front and rear etc.

The motor has 110,000 hard miles and is getting very tired and i don't know if i should trade for a new truck with a duramax or have a duramax installed in my truck.
By the way my truck is currently paid off.

You'd have a huge project on your hands to drop in a DMax. Look at the LB7 section for DMax yukon. Your 2000 is not the same chassis as the HD trucks starting in 01. It would be the same as putting one in a Tahoe, 1500, suburban, etc.

Would be a big project. Probably be cheaper/easier to drop in an old cummins. what are your goals? Doing the swap would be sweet though. TTS has done a few ECMs for swaps I know of. They did one into a mid 80's truck.