Gav,
Its an LS1 / GTO / VY pan but with an Improved Racing Baffle setup in it.
The chassis was supposed to have a cross beam located to suit LS7 sump, but was put in the wrong location at birth... and as i didn't discover it until i was lying under Ben's car one day thinking, gee, that looks different, then checked Gregg's car and thought, that looks like mine, so followed in Gregg's direction.
The baffle has little gates in it to keep
oil around the pickup.
LS1, LS2 GTO / VY-VZ Commodore Racing Oil Pan Baffle EGM-204
Dave