thanks for the reply,
unfortunately the genuine rs2000 engine and box turned out to
be a genuine big valve RS MEXICO engine and box.(1.6 and gutless)
so plan b is,flog the mexico big valve engine and put the interchangable
alloy stuff on a standard 2.0 sierra pinto.
merp has just bought some carbs off a Yamaha R1 and
another mate of mine has a big valve head so its all going together
soon.
come on merp pull your thumb out your RS

not sure about the twin 40's group 1 bit
i understood it was 44idf's