I've been busy making upgrades and updates to my 12 Port Head casting patterns. It needed both a better and more modern combustion chamber design as well as both the intake and exhaust ports updated. The head already flowed pretty good, but both the chamber and ports were designed for bore sizes of 4.125". This makes it impossible to use it on the conventional bore sizes the 250's and 292's have. I have already created a 3D model of the chamber, and will machine it this coming week. I can then add the ports to the model and then get it flowed to evaluate once I can machine them into the model. Once I get it flowed, I can then cast a sample single cylinder port and install guides and seats to see that it stays consistent with the model. The entry level head will have 1.94" & 1.6" valves with a 64-ishcc chamber.
