The 4.3L came out in the late 80's in the S10's, and was always fuel injected.
A 3.4L motor from a comaro will bolt right in using the 2.8L stuff, including the carburated manifold from the 2.8L
It's probably your best choice for that application.
Here's a couple of links
http://s-series.org/module-htmlpages...1-print-1.html
http://users.spec.net/home/emxjc/
http://www.off-road.com/jeep/cheroke...28-34swap.html
http://home.earthlink.net/~micfly/matt.htm
I haven't been on those sites in a while, so 1 or 2 links might be broken
If you can't get a manifold let me know, and I'll see what I can do. But my spare carb is junk.