Ya -10 takes a little grinding.Another nice thing about using the front plug is you can run a real fitting to it, not a banjo. A 6AN will fit perfect, an 8 will rub a little I think and a 10 would require some grinding on the case, yes they make a 10AN in a M18x1.5 pitch.
It uses a flat plastic washer.
Jim
The main reason I like it this way is because you can't use a 90 on the overflow port. Having said that you could use the front with a -10 and use the stock port as return......all the same to me.
Jim