That toyota engine is not much different in weight than the rover.
for shipping purposes
3sgte + trans _ manifolds/turbo
trans = 125-150lbs
block+head = 350lbs
manifolds/turbo = 125lbs +/-
total around 625lbs+/-
Thats from a forum so not sure how accurate.
The only thing i did not like about the westie v8 was that the engine was mounted forward a lot to get the bellhousing to clear the gear tunnel. I am going with a smaller flywhell and bellhousing combo on my installation so the engine is only about 10mm from the bulkhead. That puts it about 5" further back than with the full size bellhousing . Picture here of a westie v8 look at picture at the bottom of the page to see how far forward the engine is
http://www.seight.com/mbuild2.html
Bob