At what point on a YB head do they take the measurement to determine the port diameters for worked on heads - i've read the valve end, either side of the separation part inside the head but where is the actual point?

 

Not one single person on here know where you measure the head for actual port size?

 

I'm sorry I cannot help much on this mate Gav dimand did tell me some time back how Harvey dose it so I would drop jimbo a pm and I would think he could help you out on this matter

 

Jim replied to the same thread on the escos Site

 

I fort he would be the lad to help out on this mate