the 87 2.0L and 93 2.0L are different, almost nothing interchanges. the 93 is DOHC, meanwhile your 2.0L is probably SOHC and 2-valves per cylinder.
The 88 up engines' waterpump is driven off the timing belt. Should give ya a little hint.
The 88-92 2.2L is similar to the 92 prior motors because the motors are of the same family. The FE series engines (or F if you prefer). The 93 up are FS series engines (smaller spacing between cylinders).
1991 Nissan 240SX SE Coupe-Status: S13 Blacktop SR20DET. 12psi, 3" Apex'i Stainless DP, Apex'i racing suction intake, HKS Type-R I/C, HKS SSQV, Fujitsubo New Legalis-R type-Evo
1994 Infiniti G20 5-spd Status: I/H/E, JWT S3 cams, highport head and JDM intake manifold, outlaw engineering thermoblok spacers, clutchmasters flywheel, AGXs and Tein S.Tech springs