Martin,
Guides come in a "repair size" with a larger OD. Have you checked into those? There is not much that can't be repaired on a head.

__________________
Tony H
W111 280SE 3.5 Coupe
Manual transmission

Past cars:
Porsche 914 2.0
'64 Jaguar XKE Roadster
'57 Oval Window VW
'71 Toyota Hilux Pickup Truck-Dad bought new
'73 Toyota Celica GT