forgive me for asking a question that may have already been answered, but what did you do about the oil pan? I saw mentioning of modifying the stock pan, but I take it there is no stock pan that will allow this engine to bolt into a first gen 4x4? I may just modify the stock 3.0 pan to fit the 3.5.

I've got a 89 lwb first gen that is about to eat a con rod at 254K. I have recently procured a 3.5 sohc from a 2002 2wd sport. As far as I have been able to tell, This engine should bolt up to my existing 5speed and use my existing flywheel and clutch. It looks like the mounts will need to be modified by about 1/2 an inch. "I've got a guy" that can do a complete custom down pipe back exhaust for around $250 to $300 (he's REALLY good a that price too!) And I plan on megasquirting the thing as far as fuel and ignition.

DOes that about cover it? aside from the cooling issues you ran in to? I'm keeping it stock otherwise and it will just be a daily with a bit more oomph and 4wd to tackle minnesota winters. no serious offorading or hauling here. ALso, before you ask, I went with the 3.5 because thats all I could find. the 3.0s are getting so rare here. Plus, if you ask me the 3.0 is a bit underpowered for even a stock montero.