Anyone know the combustion chamber size on a stock 243 head?

Thanks in advance.

 

64.45 cc

 

Ok then how much is milled off the 243 to get 63cc?

 

.006 mill = -1cc

.009 mill should get you real close...depeding on what they start at. Not every head will be exactly 64.45...you should get them cc'd before and after if you need to be exact.

Lots of aftermarket ported heads get a clean up mill of around .003 also to ensure straightness. So you might only need a .006 mill.

Like I said...cc them first..and then mill to what you need.