I two biggest plusses to building a 340 really have nothign to do with cost. The bigger bore supports bigger heads with less shrouding, which is a big deal. And the smaller jouranls are less drag when it's turning. The downsides are if you have a 360, and a 340 sitting waiting fro you, each std bore and complete, the 360 parts will cost about $300 less from start to finish. And, if this is a total street car or truck, a low rpm 408 can be uilt fro a total of about $600 less than a 416 because of piston choices and crank costs. As far as which will make more power? That depends ona lot. The 340 IMO will always have the ability to make more power, because of those first two things. But whether your builder can do things well enough to get that extra power, or the budget covers it..that's another matter entirely. Cheap strokers are made from 360s. They are all faster, and all torque monsters. And most parts do interchange. A std bore 340 block is not hard to find, but the prices are going up. I used to sell at $200 for a bare inspected ready to machine or sonic core. Now that price has doubled. I can get .030 over blocks easy. Any stroker build should include a sonic test by a qualified guy with a good tester. And none should go thinner than .150" on a major thrust side, regardless of .030, .040, or .060 over. Use that as a guide, and I gaurantee you will not find many blocks that will go .060 over. It gets hard to find ones for .040 over. Std ones cost more to buy. If you dont have the matching vin on that 340, bore it, stroke it, and dont worry. If it matches the car, you should find another core, or use a 360. At least that's my feelings about it.
