72 small block water pump pulley finish

[Patrick H.]

Today I replaced the water pump on the orange 72. After the car had been sitting for 17 years when I started it up on Monday the one on the car sounded like a bunch of rocks were inside, so I knew it was time.

While doing that I happened to take note of the water pump pulley's finish (see pic). Unlike my 71 or 72 which are painted a semi-gloss/gloss black it is finished in black phosphate. I don't recall (operative word) seeing that finish on the pulley in this application previously so have no idea if this is more common or if it's 1-of-1.

If anyone else has ever noted this finish on this pulley I'd like to know.

Patrick

[Joe L.]

Re: 72 small block water pump pulley finish

Today I replaced the water pump on the orange 72. After the car had been sitting for 17 years when I started it up on Monday the one on the car sounded like a bunch of rocks were inside, so I knew it was time.

While doing that I happened to take note of the water pump pulley's finish (see pic). Unlike my 71 or 72 which are painted a semi-gloss/gloss black it is finished in black phosphate. I don't recall (operative word) seeing that finish on the pulley in this application previously so have no idea if this is more common or if it's 1-of-1.

If anyone else has ever noted this finish on this pulley I'd like to know.

Patrick

Patrick------

I have not seen a lot of 3991423 pullies (the one in your photo) which were black phosphate but I have seen some. I think that the GM specs for many pullies, including this one, must have called for optional finishes---either black phosphate or semi-gloss black enamel. Generally, only older pullies will be found with the black phosphate finish, though. I have not seen a SERVICE example in 25 years or a later C3 PRODUCTION example that was black phosphate.

[Patrick H.]

Re: 72 small block water pump pulley finish

Thanks Joe.

I'll have to see if we need to make a notation in the next version of the JG.

Patrick