That has a mess of wrong stuff. NH were non turbo charged....hence the engines in the 5T trucks, NHC 250. No such animal as a Small Cam III. BUT, If you are adding a turbo to your NHC, that would make it an NTC, small cam. Depending on your turbo selection, single or divided, they are both 25B, divided needs the auto lash screws. They still set at .018.
NHC.....N, New 4 valve head. H, nat. aspirated. C, Custom Rated.
NTC......N, New 4 valve head, T, turbocharged,. C, custom rated.
NH..... you get it.
NTCC..... Same, but the last "C" was for Ca. only, MVT...Mechanical Variable Timed. The ONLY engine sold in Ca, from Cummins in the 1984-85 time frame, fuel pressure and air pressure to control no to light load timing. Base timing set at .065 BTDC and advanced to .125. Even had a compound turbo 475!
STC......Step Timing Control. Used oil pressure to advance injection timing, base timing set at around .306 BTDC prior to fuel pressure coming up to around 85 PSI...still mechanical fuel pump.
N14......you get it, but the 14 was for displacement. Made in STC from 1991 to 1994 and fully drive by wire. 1994 got rid of mechanical and went to all electric.
Other engines, K series, inline 6 to V16....bigger now, V series, 504, 555, 903 and early, just rated by HP, like in the LARC series and the M123 series, V8 300. Not too fun to work on, V 8 470, lots of others. J series, a "C" series made in the 60's that is NOTHING like the C in the 900 series trucks. And there is more, but I am rambling.
Single entry turbo, no change to the screws, divided entry, change to auto lash screws. Part numbers are on top of the screws.
