I think the LSD would probably overpower the 2C-D regardless of the order you take them in, but I haven't tried this combo myself.
I have however combined LSD with 2C-B several times. Taking the 2C-B a couple of hours before the LSD softens the comeup but by the time you're peaking the LSD has almost completely taken over.
Dosing 2C-B after LSD works but I've needed quite high doses (>50mg) to push past the tolerance and the bodyload can be quite unpleasant (plugging the 2C-B instead of swallowing it helps with this as does cannabis).
IIRC Shulgin did say 2C-D was good for extending the duration of other substances so maybe taking it towards the tail end of the LSD peak would extend things a bit, but lysergamide tolerance is a lot for a dinky lil phen like 2C-D to push past.
Personally I'd try combing it with other phenethylamines, or maybe a lighter tryptamine like 4-ho-met, but that's just me.