Will a head exchange improve the life of my motor000 4.3

Probably not. You still have things like the rings, bearings, camshaft, crankshaft, oil pump, etc. to worry about. If you're planning on keeping the vehicle for a long time a crate engine is the way to go. Same deal for the transmission, when it wears out. The initial expense will be more. But in the long run you'll be better off. Hope that helps! Jim

A waste of money without taking care of Js0816's list. You can rebuilt the engine or buy a crate engine. I vote for another truck.