thanks dazmo - well that is an interesting sump extension, looks like they have used another factory cast, inverted the bottom 1/2 & welded to it, obviously functional but not pretty to look at. it doesnt look like it would have the same oil capacity as my rips sump. on the street, the 1st pot hole would smash that sump but that dont matter as its purpose built for the track (reminds me of my old gtr with the trust sump extension kit). this is why i like my rips sump as it does not hang any lower than the factory sump (perfect for those road undulations)...
i posted the same question on the gtr uk website & have this feedback:
The Gibson cars were wet sumped.
Dry sumping was not allowed in GP-A (At least not in Aussie)
They ran a extended sump with baffles (Prob very similar to what R.I.P.S build), They ran a stock style oil pump....Some people think they had an external pump that came off the water pump pulley, but that was a mechanical fuel pump.
so the final conclusion is that the group a gtr that was raced in aust had a wet sump with conventional oil pump
this makes those wet sump owners such as myself quite content!