IMHO, as someone who has done a swap (6.0L L96/6L90e) and evaluated all the possible choices, I do think a LS or LM2 are the best choices. There is a reason LS swaps are extremely common...they are stout, powerful and simple.
1990 era Toyota diesels are too underpowered. IMHO, they are not an upgrade for the 1FZ-FE.
5.9L Cummins are too heavy.
The smaller cummins are too underpowered, and are not very refined.
I understand purist who want to stick with Toyota, I just hope they don't mind me blowing by them going up a 8% grade.
I didn't go for the LM2 because neither Torfab's 8/10 speed adapter (pre-production status), nor a LM2 harness/unlocked ECM was available. I was following Mitch's progress though....
I think I was the first person in this community to make use of Mitch's Muscle Car Module.
IMHO, a L96, which is an iron block without DOD/AFM, will probably outlast a LM2. A L96 is a much simpler engine design. Yea, so I won't be pulling my L96 in favor of LM2.

If I got a second 80 though.....
Also, it is the details that take time....making sure the tach works, all the gauges work, check engine light works, ODB2 port is wired, Brake switch to ECM/TCM, transmission gear lever shifting, park/neutral safety switch, etc... I mean, the new 80 series Dakota Dash really helps solve these many of these details....which also was released after my swap!
