Hi Dodgeman,
not sure what series (or year) without going home to check but it is a 5 speed wagon with L20. As with most cars at this age it is sometimes a lottery as to it's originality. Sometimes anything that will bolt in is used to get a car back on the road - or if there is something worth having, buy the car and swap a lesser component in, then resell for a "no cost" part.
Anyway, it will all work out as I have a 4.8:1 C20 diff & housing to modify for my current car and the B/B H165 centre will provide a 3.9:1 alternative. I also have a H190 assembly with alloy centre (4.6:1 ??) and a steel 4.1:1 steel centre for the next race car - so I should be ok. Also have another 3.9:1 assembly from a B/B sedan if Woodydat wants a different ratio for the ute.
Cheers