Power valve identification

dart_68 said
I have a power valve that I'm not sure of the opening point. It doesn't have standard Holley markings but I'm wondering if someone might be able to identify it?

The only markings are on the top ring near the diaphragm and read J 0 5 7 - starting at the 9 o'clock position and going around clockwise @ 12, 3, and 6 o'clock. Any ideas?

Thanks.

There was a bunch of those that came through without numbers on them. The only way to know what it is in that case is to pull a vacuum on it and see where it opens. You should do that anyway because the numbers are very accurate.

And as above, a picture will help. Also look on the hex side of the valve. It could be stamped there.