As a professional shop I don't do this to my customers. I warranty my workmanship and if the repair don't hold it bites me in the anus.
Beside grinding on the cast iron valve guide will weaken it. Another option I have heard of is to pull the head drive the guide back in place and spot weld the guide inside the valve chamber as these guides are usually pushed out. Even that I don't recommend. But it is the OP's engine and he can take the risks if he wants to as he can always repair it again if it fails again or replace it. Just note there is no replacement guides.
BTW any beating on the valve guide usually means it will need reaming to correct size.
