Or-6955 cat turbo

Hi all. I have a truck with a 7fb model cat. It has a or-6955 turbo. It is in good shape. I can’t find any specs on it and wonder what it’s capable of hp wise. It is building like 30 psi and egt are good. It’s seems like a good turbo match when cruising but I’m wondering if I’m over spinning it though. It seems like I’m at the top of its capabilities. I’m worried about grenading it due to over rpm. It doesn’t look like that big of a turbo. The truck is not 400hp anymore. I’m pushing more like 500. Maybe more. Just a slight haze of smoke in hard pull sometimes. Depending on air density. Any info on this turbo would be great. I don’t want to change it if it suitable. Thanks