mate im in exactly the same boat as you i just bought a 86 vl with series 1 motor, got a 88 vlt but i cbf swapping motors so easier way im just tapping into the sump for a return, if you do end up swapping blocks mate it would be sick if you could make a big how to thread with pics on how to swap blocks for back yard mechanics ; )
That turbo is the same one i was looking at there oil cooled, cheap turbo's 8 psi springs in them they say they can handle 25psi but i highly doubt it, i wouldn't push them too hard, best bet is t3 but finding one with minimal to no shaft plate is next to impossible and everyone wants $300+ easy. i have been looking at rb25det turbochargers my mate has one on his skyline running 20psi.