I don't have first hand knowledge on this. When I was looking at options for the 2.8 in my Jeep I did a bunch of research.
You should be able to bolt the intake manifold up, and use the distributor out of your older engine. This is if your older engine has a vacuum advance. I don't think you will find one hanging off the '92 S-10 distributor.
Use care around the carb if you have the electronic E2SE on there. They're a pain in the backside. If you have the vacuum advance distributor, you should have a 2SE carb. That's easier to deal with.
There are some differences in the heads, but I think that has to do with valves.
If you are going to go with the fuel injection anyway, it may be worth your while to just take the plunge. Some of the brackets changed going from the early engines toward your '92, as did the mounting locations for them. I'm not sure on your engines. On the later engines, there is machine work that has to be done, as few of them had manual transmissions.
The swap that is most frequent is to the 3.4L Chevy from around '95. Chevy's crate engines can be retrofit to the early applications, but aren't ready for a clutch. They are assuming an automatic transmission. Time for some machine work.
This engine was used in the XJ Jeeps. I retrofit a 2SE carb and vacuum advance distributor from an early S-10 after the E2SE went south on my Cherokee.
There are upper manifold parts available for the aftermarket lower intake that allow conversion to Weber DGV or with a different part, Holley 390 4 bbl. That coupled with the later RV cam will get a bit more out of the engine.
But! The best bang for your buck will still be a 3.4L conversion. It must be the Pushrod version of this engine. After they went to OHC and DOHC versions, all bets are off.
Good luck, and get more and better information!
Given the opportunity to start over, I'd just drop a 2bbl SBC in the Jeep. More power, same basic fuel economy, and much better parts availability! Hmmmm. Maybe in a couple of months.
CJ
