Hi, here are some pictures from a Grp2 MK2 after the reg change in 1976/77. As Mike said and as you can see from underneath: 4-speed, no bespoke rear linkages, just leaf springs, two piece propshaft (due to revs?). Can't see if wet or dry sump in picture. But as Mike said, they had to run wet sumps after the reg change. And there is a diff oil cooler with pump I believe.
@ Mike: I really must see your great car live somewhere this year. Best regards!
Cheers, Stephan
