Not sure a type 9 box would be the best thing to use maybe someone else will know . i dont think it would live long driven enthusiastically with a V8.
you could use an LT77 or later r380 from a sherpa or landrover or even a rover sd1.
there are V8 bellhousings reasonably easy to get hold of for these gearboxes or you can use a landrover bellhousing 4 speed and a landrover to v8 adapter plate which should be readily available.
best bet is a V8 sherpa box

right bellhousing 5 speed and right tailshaft. you just need to fabricate the crossmember and cut a hole for the gearstick!
again RPI or Ashcroft transmissions will tell you exactly which bellhousing and first-motion shaft fits which box.
forgot to add the p6 waterpump needs the timing case to match, which is different to rangerover type, they are readily available though as its the oil pump too!