I am using the same engine mounts that you have and haven't noticed clearance issues yet.
I may have missed it as I have been concentrating elsewhere, perhaps it depends on the gearbox angle?
I will take photos of this area as I am curious to know, as I had a small run of 3 sets made which were all identical and even those were essentially based on well known mounts.
I brought the sumps in from overseas, not really interested in doing that anymore as it was a lot of trouble.
My car is at Meridian Motorsport in Moorabin, I had seen their roll cages before and therefore was confident their fabrication was right up there.
Might still be a while til the car is on the road, but I am trying to speed things up by using places like Meridian rather than my earlier backyard trial and error approach.
The car is there getting the gearbox mount, tail shaft, CV's, exhaust and intercooler piping done.
Looking at 280zx CV's at the moment as custom parts were quoted at $1700. I think sco_aus has done a lot of research in this area.