there is a mixed school of thought about where to situate the oil returns
one some cars they are below the oil line and on others above

if it's not been a problem for this sort of convertion before then i'd say it was going to be a good thing to follow the advise of people who have been there and odne that

on the other hand, putting the return ABOVE the oil level means there is no place for the oil to go to other than the sump
imagine you are cornering hard or on the brakes or whatever position is going to throw the oil up the pipe, if it's under the level then it's going to stop the oil coming back down from the turbo

swings and rounabouts really mate, but it looks like a good enough job, just make sure the welds are proper pucka jobs as you don't want then to let the oil out if they aren't strong enough because there are places where they might have poked through a little