Ginger Marshall's Mini Clubman Estate leads off the line (Imp engine on a Mini gearbox), this is 1976 it is a Forward Trust up to 1000cc Special Saloon race, the 850cc Imp was on pole but didnt win."
Ginger's brother was the mechanic. They had had 5 special blocks cast which included the block itself and the adaptor to fit the Mini box
http://www.startline.org.uk/slol21/terrapin2.htm