Hey y'all, I'm giving the old explorer a refresh/rebuild. Got a 4wd explorer to make mine 4wd. (BTW Rick, I'm trying to get the elite membership but the link is inop) and will be parting out what's left. The end goal is to make the explorer more capable and sensible for camping, road tripping, and so on. My truck is a 97 with the 4.0 OHV, auto, 2wd with 3:73 rear end. Donor truck is a 98 4.0 SOHC, auto, 4wd with 3:55 gears. My truck has a little over 200K miles. Leaking oil, runs a little rough, and just feels down on power. I'm thinking of pulling the heads, putting in fresh rockers, rods, pistons/rings. While I'm at it I'm considering some more port work, cam, tune, maybe even going as far as a turbo. What's the consensus for building a fuel efficient, reliable motor out of the 4.0? I got everything for the trans, just needs the 4wd output shaft put in. Gears? I won't be using the front pumpkin from the donor truck since it's effing 3.55. So I'm looking for a 3:73 to match my rear. Or should I suck it up and buy 4:10 front and rear from the salvage yard? Tire size is currently 31" but I'm playing around with going down to a 30 or up to a 32. I really don't know what tire size I want. Ok I do, but I don't know I want to go through the effort and fuel costs of 33's lol any opinions here? I'm not trying to run crazy trails. Just the mild stuff. I want the auto 4wd to work, and all the dash lights to work with the 4wd. Am I going to have any problems swapping stuff around since the donor truck is a SOHC? I'm considering a body lift (again) so any opinions here? My biggest concern is the rad fan. I could go electric but that's more work, and I question the reliability. Lowering the rad could work, but I don't like the idea of getting the rad closer to the ground in relation to the body) Suggestions for cams, rockers, tires, gaskets to get or avoid, etc etc is much appreciated. I haven't been around here much lately, so I'm a bit out of the explorer loop. Thanks!