A friend of mine just got a boost gauge for his 525 SC;

Where does the sender gets plugged?
Where around the intake are the plug for that fitting?

Thank You.

There is a fitting behind the supercharger, on the top of the intake manifold.

Thanks Griff. I'll have him look for it.

Do you mean at the back in the intake manifold under the supercharger/intake junction? I know that is where it is on my Merc 600SC's

or at the back of the Supercharger where there is a plug to change the oil? That plug is described in the Merc service manual for oil change it's at the back of the supercharger but is it also the pressure pick-up? That is not indicated in the service manual.

It should be at the back of the blower in front of the distributor. It is a small plug and might be kinda hard to see.

Thanks BW that's what I tought on the intake, same as the 600's

Its on the intake an inch or two behind the SC, and I think on the port side.

If the damn welder was finished with my intake I could take a pic for you. It is the only part that I don't have in the garage.