Where to start with used 4.0 on stand

[Nordren]

I got this 90-94 4.0 (think it's more of 90-92 but the stamp says it could be all the way up to 94) from a buddy's uncle lil while back without a whole lot of info on it. As far as I know the previous owner was going to put into a mustang of his until he realized it would've been to much work considering it was a truck motor. I was told the heads were ported an polished, bigger tb, mild cam, and headman headers an y pipe. The heads do look really clean but, I don't really know where I should go fixing it up; I believe it's missing a few sensors along with the obvious piping, oh an a dip stick tubing.
I have an 87 2.9 that I'm trying to swap out for the 4.0 and was wondering what ya'll thought would be good to look at and do to the motor while it's out on the stand. The 4.0 looks well sealed up with gaskets and rtv (will probably drop the oil pan just cause). But other than that idk. I've been considering buying another 4.0 ranger to get all the extra things I need but they are in short supply round my area and finding one that has a blown motor an trans might be even harder (my trans is good and I want to keep the 5spd, a back up one doesn't hurt though... Where do I start?!?!?

Any advice helps a lot

 

[adsm08]

I would do rings and bearings while it is out of the truck, unless they were just done.

As for the extras, go check the junk yard. You need wiring, the dipstick and tube from your 2.9 can be reused on the 4.0. That's what I did, and it does show the proper level.

 

[downer]

if cash is tight look for a 4.0 out of an explorer. are you going to bring a 4.0 wiring harness into the 87?

 

[Nordren]

Haha the dipstick swap was brainlessly easy, no idea why I didn't just do it myself but, none the less I probably wouldn't have unless for that comment! So thanks lol

I actually have a complete harness an ecu from a different truck. I will be looking into those explorer motors because I know there is some in town. Those things always break down hahaha.

This is my first big mechanical experience an my ol man is outa town a lot for work so I try to piece things together best that I can. Finally gettin somewhere now

 

[cp2295]

Check the rods and bearings for overheating (black color look up pics on google) if you see one pull the bearing cap and see what the bearing looks like. Check the cylinders for fresh cross hatches to see if it's got new rings