i am new to the sight, so thankyou to anyone who cares! I have been all over the net reading bout air cooled cylinder heads. i am trying to figure out what size cylinders i need for the heads i bought. it has been so long since i bought these heads i cant remember what i got. i assumed 85.5mm. so i measured inside combustion chamber on head and measured 94mm. So i was wondering if anyone could give me some advice on what exactly i am measuring. Thanks for Reading this!!