A '94 would have the LTx family engine, probably with copper plugs. The LSx engine family came out in 1997, to replace the LTx family, and is a completely new and different design:
http://en.wikipedia.org/wiki/GM_LS_engine
The LTx engine family is very closely related to the old SBC template. My '97 Dakota is similar; it has the 5.2L 318 Magnum V-8 engine, with copper plugs. The service interval is 30k miles I think. My '07 Chrysler Town & Country has a 3.8L OHV V-6 engine, but uses dual platinum plugs, and the service interval on those is 75-100k miles.
