Have C heads currently on my 65 400. Just noticed the pushrods are ever so slightly brushing up against the hole in the head. Dad didn’t realize that the 45 degree block needs a bit more pushrod clearance in the head. He also didn’t realize it needed a different cam. Already fixed that though. Actually ran the engine like this, luckily didn’t tear anything up. Pushrods have only the slightest signs of rubbing, basically just a small line where they are a bit shinier. It was most noticeable when I had them all out and they all had a stripe on them in the same spot. Red flag.





Anyway, it should not be an issue to enlarge the C head holes, but seems like pulling them off is the only safe way to fix it. And if I do that, I’m tempted to put the Edelbrock aluminum heads on. Dad always wanted them but couldn’t swing it so I think he’d dig it if I went that route.

Question is, do the Edelbrock heads clear the pushrods okay on an early big block? Maybe even if I went up to a 3/8 pushrod? Thanks again for all the help.

 

Edelbrock heads are apples to apples. They’re configured for a 39* block, so if used on a 45* block you’ll still need to enlarge the holes or machine them to a 45 like I do.
And they won’t be ready for a little whiile yet.

 

Thanks. I may try hitting the holes with a right angle die grinder first. If I mask everything really well and run a vacuum it should be okay. Seems like I don’t need to take a lot off.