Hey John, good question. in my experience the lapping compound is working its way out in both directions across the entire face while twisting anyways so i dont see the need to tap, then when cleaned off you can visibly see the contact patch. I typically see people tapping to re-introduce lapping compound back onto the seat and valve face, then you can continue lapping. Again, you're only trying to get the surfaces to know each other. You're not trying to remove excessive material. 1 maybe 2 passes is plenty. Any more, and their is an issue.

Unfortunately the only option currently on the market is used oem or new oem. which is very expensive. we do have a cylinder head we are parting out if you wanted to email us on a used set colton@boostfactory.ca hope this helps!

Hey, good question! Nothing considerable. You are only trying to get the valve to know the seat again. You're not trying to machine anything down. You would be hard pressed to make a significant change in height without our first damaging the seat. The valve installed height is relatively the same as before, and the valve shim thickness reflects that!

@@boost.factory '003?

Hey Chris, we have a pointed steel tip that we weld onto the ball, then that threads onto a slide hammer, a couple taps, and they're out!