well if your missing one, id get a 2.3 because there plentyful and have a little more go. any 2.3 with a distributor and carb will work, mabey a few minor mods, but its simple, although any 4 plug 2.3 engine with a distributor hole will fit and work, you'll need the right intake manifold and carb. plus the duraspark distributor to be direct drop in for your truck.. how much of the truck is there as far as stuff like electrical, fuel, moto mounts, etc.. and if your missing a trans, IIRC, the 2.0 mostly came with manuals. 87 used a mazda TK5 trans, which can be found in pretty much any 2wd ranger made until 87.. although a new trans like an m5od will work also as you got the proper master cylinder, mounts and crossmembers.. if your good with electrical, you can use the EFI that came in 85-94 rangers with 2.3's