340 upgrades.

Those are good heads and not much rust. Have you seen some of them on E-bay? I would just keep what you have. Just get 10.5-1 pistons and if you want have the heads redone. But if they were redone and never used -even for 25 years-they should be ok. Might want to lap the valves if theres any rust on the seats. The 360 and 340 used the same heads back then. You get between $200-$400 for the heads on E-bay and could get Eddys heads new for $1300 but I would keep those heads if I was you. $10,000 for a motor is nuts-unless you have money to burn and if you did I sure would not get a Mopar factory motor. Have a good machine make it up.