The Ford Ranger Edge is really no different than any other Ranger in that generation. "Edge" is just a trim name. My 1999 Ranger is badged 4×4 Off-Road, which they ended in 2000, replacing it with just a 4×4 badge on the tailgate. Ford added the FX4 badging toward the end, as well as revived the "Splash" trim at another time. For most intents and purposes, they're practically the same truck with only slight differences. Rangers in that generation came with either a 2.3L I-4, 2.5L I-4, 3.0L Vulcan V6, or one of two 4.0L Cologne V6 variants, SOHC or OHV, all depending on year. You either have the 2.3L, 3.0L, or the SOHC 4.0L, so anything pertaining to those engines will be applicable to your truck. 

If you have an automatic transmission, it's a 5R55E or 5R44E. They're upgraded versions of the 4R44E that is in my truck. The smaller engines get the 5R44E. The standards were the same throughout the generation. Hope that helps.