Well from my signature you can see the way I'm going. From what I've read on here, I would not rebuild an IDI. They just don't seem to take to it well. Members have swapped in rebuilt engines and had problems, and done it themselves and had problems shortly (not all, but way too many for my comfort).
If you do rebuild it, you still have to deal with injection pumps and injectors that crap out every 100k. Then, unless the batteries, starter, cables, and fuel system are 100% it won't start well in the cold (maybe not a big deal for you). Cheese **** fuel return system that will need annual attention. Mechanical fuel pump that should be removed, thrown as far as possible, and replaced with an electric pump. Head gaskets that aren't known for staying in place for too long, and you won't be able to push much pressure to it or they won't last at all. Little aftermarket support. Better have a great cooling system or it won't stay cool on hills even empty. And you'll be living with 130-200 hp, which does not work for me with 6% grades at 7000 ft even empty. Heck my IDI couldn't handle a 3% grade of any length empty, without a downshift, here at 7000 ft.
Last trip up the hill from Phoenix I had my IDI floored, alternating between 2nd and 3rd gear, watching the water temp and pyro like a hawk. When I made trips around Colorado, I drove around the section of I-70 west of Denver, and Leadville, because I wasn't in the mood for 2nd gear empty. Drove my 97 home from Phoenix with the Cummins in it, with holes in the intercooler leaking boost like crazy, still pushing 30 psi and didn't even downshift out of 5th once, and had lots of power to spare. Of course, now I'm re-doing the swap due to a non intelligent life form previous owner, and there are lots of things to figure out and overcome. From what I've read, the fuel system is pretty stout (just the size of my P-7100 compared to a Stanadyne DB2 is crazy, plus it has an engine oil supply. Though the IPs are expensive. Just look on a Cummins forum, and bad IPs are hardly talked about, here its about every 4th post. No glowplugs, just grid heaters that often aren't necessary. NippoDenso starters that can be rebuilt yourself easily. Vacuum pump that you can rebuild yourself. No need to mess with turbo up pipes, just bolt it to the manifold and hook up the exhaust. Need to time it? Less than $200 in all mechanical tools and you can do it easily, without guess and checking with hard to reach nuts to adjust the IP. The timing will stay that way for many miles, and you don't have to rely on old electronics to time in the future. Advance it all you want because there's no glow plugs to burn up (though other things may not like too much timing).
You asked for opinions, so there's mine. Hope I don't offend anyone. Some people can make the IDI work for them, I did for 5 years and am done with them.
