Diff <-> Engine alignment/height

[Eternal]

OK i got the engine crank and gearbox to dead center that was quite easy.
The problem im having is getting the diff and gearbox to line up. Im 15mm out but that left 50mm of sump under the chassis rails. I could get the cast ally sump cut down but its winged and would cost a fortune to get done. Also have a steel sump but that needs baffles and all kinds being done to it (same height as ally sump).

My question is this... what is the max drop that is allowed from the engine to the diff? As if i can raise the engine a little more that would solve all the problems. Also the top of the engine is 200mm above the top chassis rails so thats ok the hood im going to make will have a bulge so can go higher if needed. Any advice more than welcome!