Putting 1999 6cyl in 2000 4cyl Dakota Sport
 

Afternoon all -
Last week my 2000 4cyl Dakota Sport starting banging like crazy. I had a Dodge mechanic check it out on his off hours and said the noise is in the bottom of the engine and most probably a rod bearing. The engine has 191,000 miles so it had a fairly good life. We found a 1999 Dakota with a 3.9 6cyl with 110,000 miles. I can pick it up for $150. The guy that owns the wreck only wants the truck for the bed. And he'll guarantee the engine for 6 months. No front end damage so I can probably get the radiator, AC, anything from under the hood I need for the $150.
That said, can we pull my 2.5L and drop in the 3.9 without too much hassle? Will things line up, especially my 5 speed transmission? I have some guys that are motor heads that can do most of the heavy lifting for me.
I've been down for a week and would like to get this moving over the 4th holiday.
Thank you all for any input.

Mechanically, you'll need a V6 M/T flywheel since the donor truck is likely an automatic. Bellhousing should be the same as as I recall. You may run into a snag on motor mounts, the frame changed slightly in 2000 but you might get lucky there (It's like a 1/4" adjustment).

The electronics are where I am not sure - if the 2000 dash is electronic, then you'll have some (alot of) electrical issues. It would be best if you found a 99 engine harness and PCM.

You should be good then, pull the engine harness and computer as one big assembly. Shouldn't be too bad of a swap.

No, the PDC is the same for all engines. You just need the V6 harness and PCM. If both are a manual trans, that makes your life better as it will be plug and play.

Tranny should line up? Should I replace the radiator and fan also?

I'm not sure if the rad/fan is same from a 4 to 6 or not. I know 6 and 8 are same. Trans should line up, want to say both used the NV3500 or 3550 but i don't know that for sure....

The more I think about it from Dakaz's threads, i think the radiator is different.