If they are the original '88 guides, be advised that the material used has been upgraded 3-4 times since your car was built. Also, M103s are tough on guides given the way the valves are actuated - I understand there are a few aggressive angles in there that can be tough on the guides.

If I were you (and I was in the same situation last yr. with my '88 300TE) I would do the guides now, and forget about them for the next 150-200k miles.

__________________
"If God had meant for us to walk, why did he give us feet that fit car pedals?" Sir Sterling Moss

Michael
2014 E63S Estate
2006 SLK55
1995 E500
1986 Porsche 944 turbo