Dear JH 86 300E

Addendum: This is a 92 300E and we live in Contra Costa County, Bay Area, California. Our mechanic recdommended a valve guide fix for around $1500-2000. He didn't say anything about a full valve job. He has to send out the head, so we may as well grind all the valves while we're at it. Correct?
Thanks for your imput.

300E Russ