I am running the Rover 3 litre straight six with Weslake head from a Rover P5 in my 86inch, it is a tight squeeze for the pump but from memory it was the pump with the kit.
When i bought mine he still had several left with pumps so i got one. I will take photos tomorrow and post up showing how i fitted mine to the Series 1
As a newcomer to this forum - i thought to say hello before joining the discussion - so hello.
The ZF box is a really simple system to fit to a Series 2 or 3, i fitted one about 3 years ago to 86inch Series 1. If fitting to S1 the bracket wont work with out modifications but is easily "do-able" with a grinder and welder.
I have had no problems with mine in terms of leaks etc and does not seem to place any more stree on the relay than a standard steering set up.
Overall well worth the effort and makes parking a dream