BBC Crankshaft Identification

[Mark F.]

I'm trying to verify if I have a 396 or 427 crank. It's casting number 6223 and came out of my 68 427 L71. All the books I find say that I measure the 3rd counter weight back from the front of the crank. If it's 7/8" wide they say it's a 427 but if it's 7/16" it's a 396 crank. All of my counter weights measure 3/4". Any idea what's going on here? I've verified that it's a forged crank.

Thanks

Mark 39215

[Joe L.]

Re: BBC Crankshaft Identification

I'm trying to verify if I have a 396 or 427 crank. It's casting number 6223 and came out of my 68 427 L71. All the books I find say that I measure the 3rd counter weight back from the front of the crank. If it's 7/8" wide they say it's a 427 but if it's 7/16" it's a 396 crank. All of my counter weights measure 3/4". Any idea what's going on here? I've verified that it's a forged crank.

Thanks

Mark 39215

Mark------


Cranks with forging number "6223" were used for both 396, 402, and 427 engines and are VERY common. I believe that Chevrolet used different methods of machining and balancing these cranks, so I don't think that measuring counterweight thickness is a reliable way to id these cranks as to finished part number. If the crank came out of a 1968 L-71, my suspicion would be that it's an original crank for that engine.