340

all 1973 340's were cast crank external balance engines, early 1972 340's came with steel cranks.

Do not worry about this, you can build a very good street performance or street/strip engine out of a cast crank 340.

Rebuild the short block, upgrade the heads to 2.02 intake valves with 1.6 exhaust valves with hardened seats (I am not sure if the '73 "J" heads are hardened). install your preferred induction system, cam, exhaust and hang on!!

Before you invest much into this engine, verify it is stock bore, boring 340's beyond .030 can be risky business. You will need to sonic check a 340 block to verify it can be bored to a diameter over 4.070" bore. If the engine is already .030 over with lotsa of miles then there might not be enough material left in the block to bore it .060 over.


Bob