I'm three years late to this thread, but reading it sure provided some reassurance. I bought my C.I. head 10 years ago from Mike Winterboer. My 1968 Mustang coupe restoration project has been idled for nearly that long (hey... life gets in the way!), but it's ready for me whenever I choose to resume. Back when I started assembling the head, I noticed this same issue. My pushrods interfere with the inside edge of the holes. I used a large rat tail file to remove some material on that side of the holes, but I stopped short of finishing the job before I took my long break from the project. I got a really uneasy feeling filing away on this head, because I kept thinking I was going to file through into the coolant passages. I even considered ordering a Yella Terra roller rocker assembly thinking it would have different geometry and the pushrods would clear. That's an expensive path to take in the interest of experimentation - maybe someday. I plan to finally resume the project this winter, and have just a bit more work to do on the pushrod holes to allow for clearance. Seems odd that there hasn't been more mention of this? Here's a photo that illustrates the issue: