"The T56 sits a little further back then the rover gear box but i think in a really nice position.You will need to modify your center console if you want to keep that standard look.
The tunnel had to be panel beated a little bit with a hammer but that was about it.And of course a new hole cut for the T56 gear stick to poke through.
As far as engine conversions go it wasnt that bad.Although i didnt do it myself i had someone else do it for me.All that was fabricated was the gearbox cross member along wih the new engine mounts of course.I had a new tailshaft made up as well.The radiator is from a subaru 2.0 litre turbo model.Im not to sure yet how this will hold up but hopefully it should be ok.The hose outlets are in the right spots to suit the LS1 hoses.Plus it pretty much fitted up where the standard radiator was without having to get a custom radiator made up.The other thing you will need will be a rear hump sump.I got mine from a place in America.It was cheaper to do this then mod the standard one.
Its still a work in progress until i get some more cash unfortunately.The fuel system is just about sorted and i need to get some custom headers made up.The drivers side header i have wont clear the steering column.But the passenger side has heaps of room.Once i can afford the exhaust work i can do all the other little things.Like power steering hoses and wiring up gauges.I cant wait to get it going.One of these in a car like your Rover would be an awesome sleeper"
Can't think what subaru radiator he is refering to, as none I've ever seen have suitable end tanks for an LS. They would be opposite to what would be needed.
T56 shifter position on a camaro box is almost same as a LT77. Viper would be further forward, GTO or monaro would be slightly further back.