Generation IV Internal Engine - mystery piston...help please

So I bought a disassembled ls7 shortblock below are the pictures of the pistons. I am having a hard time getting info on brand and specs. The numbers on the skirt are

809ts & 28583

http://i51.photobucket.com/albums/f400/nicktomstew/20120710_172120.jpg

http://i51.photobucket.com/albums/f400/nicktomstew/20120710_172156.jpg

Thanks, Nick

Anybody know how to get info on these

Those were some proprietary Diamond pistons we had made for us in large runs. They were setup for 4.125" Bore, 4.000" Stroke, 6.125 Rod Length, -3.84cc Valve Reliefs. I believe their valve reliefs were setup for the ETP LS7 heads.

Thank you Matt... everything I was looking for. Just one more thing, can I get some compression specs, please?

Compression distance was either 1.115" or 1.120"...I am sorry I do not have the exact on them because we haven't had a set made in close to 5 years.