Yes. Cast 340 crank in a 318. It has been balanced. I had a 318 that had a stripped balancer bolt and I tossed the crankshaft. I had a ‘73 340 crank laying around. Parts I already owned. If I had to buy a crank I would have bought a 4” crank. I’m not trying to pull stumps or drag race this truck so I figured a low budget build would be in order. Intake and heads were cheap and I already had the block and a crank.