Originally Posted by 440mopar
Been away on vacation so I haven't worked on clearancing the pushrod holes yet but I plan on picking up a bit this week. I will get a bit for aluminum but have one more question. Should I get a 1/2" diameter bit (the size of the pushrod hole), insert it in the hole and just work it upward till I have the needed clearance (basically ovaling the hole vertically) or would it be better to do the same but use a smaller diameter bit like 3/8" (the size on sizediameter of my pushrods) and just notch the hole at the top where the pushrod is making contact? I hope my question makesze sense.


You can’t be size on size with a burr bit. The bit always needs to be smaller than the radius, or you will get impossible to control chatter.


"use it 'till it breaks, replace as needed"