Well, I got the first one completely ported and moved to the second one. I started with the exhaust ports and did the usual bowl blend, opened the port to full width where it knecks down in the middle of the port run, removed all the foundry flashing marks, made a wedge shaped entry and exit around the valve guide and lowered the valve guide a bit, smoothed and radiused the entire port and finished up all 4 ports before moving to the chambers. After I was just about finished polishing the chambers I noticed thru my dirty safety glasses that there may be a crack coming from under the valve seat and wrapping up and into the chamber going acrossed the face of the chamber. I stopped and got the MAGNAFLUX penatrant cleaner, penatrant, and developer. I cleaned all 4 chambers and applied the red penatrant dye, waited 10 min and did my cleaning, then applied my developer.....brighter than the sunlight on a hot summer day was a ugly...nasty...bright red crack just where I suspected. So now I am looking for a replacement head. Im mad!