TRying to decide wether to rebuild the 3.9L V-6 when I finally get to that point or Get the 318 and put that in. Not sure? Will not be pulling much stuff, just want a good Long lasting motor. Can you help me with this, also how hard is it If the 318 is a better choice, how hard it is to put a 318 in, after the v-6 has been taken out. Do I have to do a lot of Modifications to get that motor in. Thanks for any advise you can give me.

 

The 3.9L is a 318 with two cylinders cut out of the casting. They're essentially the same motor.

I'm not sure what would have to be changed to put a 318 in though. I'm guessing motor mounts, transmission (not sure which one your truck has now) and maybe the driveshaft.

 

208,000 miles on my 92 d150 3.9, still strong.

 

Wow 208K miles, dang,, OK,, well,think that answers it! thanks alot. I have 138K on mine, but i just bought it, and it looks like it was rode hard and put up wet! Thanks yall!