Mitsubishi 3G Valve Lifters
One of the more annoying features of a Stealth motor is lifter tick, especially when the car is cold. Tick tick tick tick tick. Bothersome, and it might be masking other, more important noises.
The later motors from around 1998 or so came with revised lifters that greatly enlarged the oil port, allowing more oil to flow into the lifter, sooner, and (supposedly at least) eliminating lifter tick. At about $100 per set, this was just too good to not try.
The oil port on the end seems pretty large.
...to be continued