Looking for engine replacement on a 2002 v6 4.3L Chevrolet Silverado

I am looking for engines to use in my pick up truck. I know that the engine I have is also in other GM/Chevrolet vehicles. What vehicle models and year ranges should I be looking for in terms of a replacement and/or swap?

Various specifications found in my owners manual are below.

• Year: 2002
• Make: Chevrolet Silverado
• Model: 1500 Regular Cab Pickup
• Engine: Vortec 4300 (automatic)
• Type: V6 4.3L
• Vin Code: W

I found this wiki page, but I am not 100% sure what I have. I do understand these vehicles are potential candidates for having the same engine. However I do not know the compatible dates ranges for an engine swap.

Other models with same engine (unclear on swap-able date ranges):

• Chevrolet Silverado
• Chevrolet Express
• Chevrolet Astro vans
• Chevrolet Blazer
• Chevrolet S-10 (2WD)
• Chevrolet S-10 (4WD)

The engine needs to be swapped due to possibility of a cracked head or damaged head gasket. Engine oil and coolant has been mixed. Any and all help would be greatly appreciated!