Toyota 4Runner RV6 engine woes

am currently stripping down the engine as it's recessed a couple of valves (important - especially if you're on gas get the shims checked regularly!), I don't recommend working on this beast, more pipes and connections than you can poke a stick at. Anyway, in case the heads are too far gone does anyone have a good 2nd hand engine for sale(3VZE 3 litre V6) or perhaps interested in buying a good 4Runner for an engine conversion?(covering all my bases here)