Disco 1 Rear diff seal

Hi,
Just removed old 3 bolt flange and ready to fit new 4 bolt version and get rid of rubber coupling.
How far does the oil seal sit into the diff nose? I've got it in flush and straight but it will clearly need to sit slightly further in to avoid rubbing against the dust shield. Will a few mm do the job ?
Thanks

yes,there is a slight step it goes down to

Thanks James. So a few taps with an appropriately large socket on the new flange will do the job?

just be careful garter spring doesnt pop off, i tend to fill inner with petroleum jelly to hold it in place if tapping a seal in,rather than the press

Ok so the seal is seated nicely, the new flange (+ dust shield) is bolted on (with old spacer washer behind new nut) and torqued up to 130N.
now I'm worried about the play. There is back/forward play behind the nut/spacer as if the flange has slid too far in along the pinion. Is this normal? The whole operation is to get rid of drivetrain vibrations so I need to get this right!

Just double checked part numbers. My flange kit is STC3722 appears to be way too short compared to the original flange :


Back to the catalogue and I see there is a different flange kit: STC4858. I guess I have the wrong kit !

Not a big issue u just require a spacer, u have purchased the 4bolt flange that's fitted the the later D1 V8 which doesn't have the donut coupling.
To fit that flange to match your original there's a spacer available, what I've seen its usually listed alongside the flange kits therefore your supplier should have one.

539745 is the spacer you need

Thanks James - mystery solved!