Hi,
OK, my lines come straight forward from the engine mounting adapter, then make a near 90deg turn under the power steering pump up to the left fender. Filter is right behind the headlight.
The replacement lines I'm looking at online may not have two sections of hose as I mentioned earlier. It appears that one of the lines has some sort of sleeve on it. Probably to prevent rubbing. Lousy picture. So my earlier statement wasn't exactly correct. Lines may be the same, have the same bends as mine. Wish I could eyeball one.
But, if it's tubing & not hose underneath, how do I get them out & new one in without removing the radiator?
Hose/line assembly:
There's a hose/line assy online (Ebay item# 370181557716 ) that supposedly fit 88-94. Going to the sellers store, I found another hose/line assy listed for 94-95. I sent e-mail, mentioned adapter problem, waiting for reply.
Adapter:
Found a number on bottom of my adapter = 10054756 . Not a good GM number. But, checking with a dealer, adapter #93802307 is good 88-99. Maybe it has longer attaching bolt or bolts. So yeah, maybe I need the whole hose-adapter package. Naturally, no one stocks anything.
Maybe visit a salvage yard tomorrow.

 

My '89 S10 oil filter lines fit the adapter on the '00 Jimmy engine I put in, no problem. I ended up buying a new set after I damaged the old ones while the engine was out for the swap. Was Dorman 625-102. Came with all the seals plus loom on one line for protection. I ended up covering both with loom from the Jimmy for extra protection - don't want to do this again, especially with the engine in.

You should be able to slide the old lines out easy if you remove the radiator, condenser, & grill and pull it forward. Could skip that step altogether if you unbolt that driver's side mount & jack the engine up -- that way you could swing it out the side. Probably easier/faster that way than removing everything up front there.

This pic is the newer engine, so yours is going to be slightly different in the mount / oil pan area. Lines are identical though - these are the new Dormans with the loom installed (line above it is the block heater cord, also wrapped in loom) :

 

I cut mine then was not bad at all....(no cooler) 88 S10 Blazer 4x4

 

Cut the lines, huh?
Ummmm, so how did you install the new lines? Didn't cut them first, did you?
(Sorry I'm such a smart ***)

No cooler on mine either. Should be same as mine.
Did the lines fit your old adaptor?
I don't suppose you could see if your adapter is stamped #10054756.
Did you use the Dorman 625102 hose assy?
Did you have to R&R radiator/shroud, or loosen mount/lift engine, or whatever?

Just trying to determine what I have to disassemble to replace the lines in one piece. Just in case the new lines don't fit my adapter & I re-install the old lines.

 

in the pic above are the lines one side from remote block to engine block which is the only one you need. those are the lines that you would have to get because thats what they sell. you cant get the other style lines anymore which is why u need the oil cooler adapter which is also in the pic above and use 95 cpi + and 96 sfi+ for the adapter.

 

10/21/11
I might make a more detailed tutorial. Sure would have helped me.
I'll include a couple extra photos..

EDIT:
Added 3/7/12
Here's my more detailed repair:

I have a 1989 S10 Blazer 4WD 4.3L. I do not have the oil cooler.

Why I replaced instead of repaired my oil filter lines. See photo. I considered the cheaper repair job, until I removed that bracket from the PS pump.
At least I found a use for my 3ft extension. Should have been 2.5ft.

I replace my hoses with the truck on my shop floor with the front end on a couple ramps. A hoist would have been easier, at least for the underneath work. I must have crawled out from underneath 20 times.

I removed the upper shroud and fan for easier access. I would have removed the lower half of the shroud too, but the shroud IS the radiator support. Necessary to remove radiator to remove lower shroud. Too much trouble. Left radiator in. (cheap-*** radiator)
Loosened but didn't remove that lower valence panel. Bent it up out of the way. (My 3ft ext was a couple inches too long)

Draining the radiator? Probably don't need to, but I replaced lower radiator hose while easily accessable. Syphon, with 6ft plastic hose. I couldn't get that damn plastic petcock to work. (have I mentioned cheap-*** radiator)
Drained the PS reservoir the same way (syphon). Needed fresh fluid anyway. PS hoses are in the way for tubing removal. Disconnected the PS return hose. (and replaced it-old hose) Was able to work around the pressure hose, so I did NOT disconnect it.
Remove PS bracket bolt. Remove bolt from fender filter housing/oil line. Disconnect oil lines.
Remove oil line bolt from bottom end using 2.5-3ft of extensions and maybe a swivel. (Bolt should same size as filter end. Use a 6pt socket if possible). I used a 3ft ext. I threaded it in from the front bumper area. I used a swivel wrapped with masking tape so it wouldn't flop around like a wet noodle. You might have enough "flex" using 2or3 extensions. I couldn't really get my hand up in there, but after I loosened the bolt I was able to turn it (the ext) by hand. After removing extension I gave the lines a light tug and it popped loose from the block adaptor. Bolt fell on the floor at this time. Don't loose that bolt. Using drip pan, I let hoses drain. Drink beer. Be careful not to misplace any bolts. Most are metric and odd length. Hard to find.

R&R Oil Lines:
Note: Agasin, my 89 S10 does not have the oil cooler. This repair is for the oil filter lines only.

The lines came out from the top, not the bottom as I thought. It doesn't look possible but there is enough room to pull them out. Actually I laid underneath and pushed them up while pulling the tubes forward. They came out in a big "C", a half circle. Once the lines are moved forward a few inches, the rear end of the lines will drop down and the lines will swivel up and out. After the 'end' was past the eng mount, I crawled out from underneath and easily pulled them out leaning over the front fender. That PS return hose would have definitely been in the way. Make a note of exactly where the lines came out. Or take a picture.

Block Adapter:
I had to R&R it to scraped off (I mean remove) the old o-rings. It's aluminum, so be careful. Smoothed it up with a sanding block. Clean up area & re-install adaptor.

Installing New Lines:
The new lines should have plastic end caps. Check to be sure the seal is there, them put the end caps back on. Holding one end of the lines near the fire wall, thread the lines down thru where the old lines were. The new lines are more flexible-alot easier to handle. You should be able to wiggle them down to near final position. It's tight, but they will go in there. It's kinda like installing a tailpipe on a 48 Buick. Got to go in there somewhere. If plastic cap falls off, clean it up and try again. Don't tape endcap on. Can't get fingers up there to get the tape off. They should stay on. With lines in place, remove plastic end cap with finger or long needle nose. (I'm assuming you cleaned everything really, really good before you got this far). Align lines & adaptor with one hand, and holding lines up with other hand, slip lines onto block adaptor. Holding lines steady, insert extensions and socket and bolt thru from front. Snug up. Look OK? Tighten. Done with hard part. Beer.

The block adaptor/tubing bolt was the hardest part. Took me a couple tries. I finally taped the bolt to the socket with masking tape. Turning ext by hand, I finally got the bolt tightened. But the socket stayed on the bolt! Can't reach with fingers. Trying again I taped the bolt to the socket, then taped the socket to the extension with duct tape. Got lucky. I suppose I could have taped the bolt to the line end somehow. Anyway, my socket/tape method worked.

Align lines with PS bracket. I had to tweak my lines slighty. And I used a small piece of old innertube as a cushion for the PS bracket.

I had one (1) screw left over. Make a mental note of where all your bolts/screws go.