engine # *6392956 someone?
 

This is in a '76S
My dads old car. Once a bad leaker but now dry???

Looks like a '69S.

... or a '79 3.0 SC - Porsche in their wisdom used this same series of engine numbers for both years !

Installed in a 76 car and no oil leaks I'd guess 1979 3.0.

Is it mag or aluminum?
We could use the designation number (930/??) to be certain.
This number is located on the engine case on the right side of the fan housing.

Case casting number will also tell us which one you have.

That number looks like 930-OS
Does that make it magnesium or aluminum?
Still a '79 3.0L?

79 911 SC 3.0. Aluminum
This is a very nice up grade for a mid 70s 911.

More than likely 930/03 - that would concur with it being a '79 SC engine (aluminium crankcases).

930/05 is a Japanese-spec '79 SC engine (serial number would be 619XXXX).

930/06 is a California-spec version with serial number in the form: 659XXXX

YOO DA Men!
laquer thinner/toothbrush....it is a "3"
Thanks so much for your help.

I'm a huge fan of 1974-77 cars with an upgraded engine. These cars are so neglected and unwanted by the Porsche community for their 2.7 engine problems, that you rarely see too many these days. Installing a 3.0 solves 95% of the engine problems (replace head studs and install Carrera chain tensioners while you're at it), and really makes these narrow body cars sought after.

-Wayne