yes, the C8.3 is a wet sleeve
and depending on the config, both engines were dogs for what they are LOL
If your talking old mechanical (pre ~94 for the DT466, ~98 for the 8.3), they were both available with bosch inline pumps (only the later DT466s used a P7100, earlier engines used the bosch MW). some were P7100s, like you would find on the dodge 5.9, some were different models. but for the most part, as long as your not looking at the bottom end of the HP range of these engines, youll likely be looking at one with a 12mm pump which will easily make some more power.
Looking at later engines:
The 95+ DT466 went to electronic unit injectors, leaving not so much "room" on the table, though still pretty reliable, eventually taking another step in earl 2ks and going to VGT keeping the electronic unit injectors
the C8.3(now the ISC) moved onto the cummins CAPS fuel system which while working did "ok", but was pretty unreliable (caps pump failures are fairly common, dumping fuel into the oil!) and eventually moved onto commonrail in early 2k