Installed a new Merc 383 stroker, runs great, but my VDO tach does not work. Checked all leads and there good. Is this gauge not compatible with this engine? Do I need to buy a new tach gauge? Is there an adapter? Any thoughts?

anyone?

Are you using the gray wire?

I have a MSD tach adaptor if ya need one?

Yes I am using the gray wire. THe Tach worked with my old 350 carb motor so I think it is a signal issue. All leads are correct. i hear about the MSD issues adn am wondering if they are the same. Do you think the msd adapter would work?

I am pretty sure it should be plug and play, I mean the old tach should work without doing anything. I had an old 1989 VDO tach with a 454 Mag carb, and then later installed a 1999 454 Mag MPI and the VDO tach (and all other VDO instruments for that matter) worked perfectly with the new engine.
Do you have access to a digital frequency counter that you could hook to check the wire going to the tach ? Or an oscilliscope ? You basically need to check that you have the proper signal on the wire going to the tach. If you do have the proper signal on the wire going to your tach then your tach is bad. If you don't have the proper signal then you need to find out why.