Yes, a 350 (5.7L) engine from a 1993 Chevy 1500 pickup should fit into a 1994 Chevy Cheyenne that originally had a 5.0L (305) engine. Both trucks share the same basic platform and engine bay dimensions. However, you'll likely need to transfer over some components, such as the intake manifold, accessories (alternator, power steering pump, etc.), and possibly the exhaust system, to ensure everything lines up correctly. The transmission will also need to be compatible (most likely a 700R4 or 4L60E). You should also check for differences in wiring harnesses and possibly computer modules.
While it's mechanically feasible, a professional mechanic's assessment is recommended before undertaking such a swap to account for potential unforeseen complications.
