Should the fuel injection pump timing and pump main rack require adjustment as part of a tune up on a 1969 280SL? I'm getting conflicting advice on this: my regular mechanic says it should not be touched, and will be difficult to correct once changed. Another mechanic wants to adjust the fuel injection as part of a tune up.

So my question - should the fuel injection pump timing / pump main rack ever be adjusted on these cars? Is specialized equipment required to do this, or can any mechanic do the adjustment? What equipment should the mechanic have on hand to do the job properly?

Thanks in advance for any insight.

Steve
1969 280SL