Just curious what others have seen for variation in combustion chamber volume measurements when CCing heads???

Just had a set of 906 heads freshened up at the machine shop and my combustion chamber volumes vary between about 82/83 and 86 CCs, IIRC.

Based on everything I hear about the lack of consistency in Mopar factory tolerances, I assume this is pretty normal??? What have you guys found?

Also, any general consensus on how close these numbers should be for a well built street motor?

Thanks