[ricola]

Well, I have more information now... Mike Ghia tried fitted a 996 disc to a steel 944 arm but the bell is too deep which means the disc can't push on far enough as it hits the caliper bracket before meeting the hub face. It is about 5mm. TO fit a 996 disc would mean fitting a spacer of about 5mm under the disc which would widen the track an additional 5mm.

He tried a 993 disc but the bell was too short by about 5mm (the h/brake pads were still visible), the hub could be milled down at the back and a spacer used under the castle nut, the advantage being that you could reduce the track increase of the conversion by about 5mm but I don't know about clearance of the centre cap.

Finally, the 86 turbo/928 disc should bolt straight on.

So, I am undecided about 993 or 928 now, I'll trial fit my wheels to the drums and try to estimate if I need the reduce the track at all to neatly fit everything under stock wings and if I do I'll go 993, f not, 928!

Thanks for all the input guys, nice to have some definitive answers!

Rich