Is it that you have the brackets and they don't fit? Or you're trying to work out how they fit so you can make some? If it's the latter, I have a 280 kit somewhere, if I can find it I could take some photos if it'd help? Or sell you the whole kit....?
"Hard work often pays off after time, but laziness always pays off now."
Hi, Does the place you bought them from have a technical helpline that could assist? Sorry, I couldn't resist! If you post some photos on here of the issue, somebody might be able to spot something that you might have overlooked.
Long time ago, but I remember I had to drill the struts, removing the threads, to make the bolts go through. I also had to grind a bit off the strut somewhere too. Give Andy Craig a shout, he was my mentor for the brake conversion, had the brackets cut and supplied the bolts.
Beakster is right, to fit the brackets you have to drill the original threaded holes out to remove the threads and allow the bracket to be fitted on the rear. From memory you also need to grind / file the two tabs with the threaded holes so the bracket fits flat, if that makes sense. I have the 260 kit but since my struts are off at the moment i cant show it assembled. Sounds like you might need to tweak the brackets on your kit too if it's fouling but do double check you've got everything the right way round before you do.
The conversion is Def worth it, it makes such a difference, it's just the suppliers customer service sucks.
I have just bought the 280 kit and if the 260 is along the same lines, which the kit of bits looks like, then the explanation he gave to me is as follows.
Drill the struts to remove the thread and allow the Allen stud to pass through. Mount the plate behind the strut mount. Use one of the spacer washers between the strut and the plate. You'll probably need to flatten the rear of the mount with a file. Mount the caliper bracket on the plate, using another spacer washer between the plate and the bracket. Fine tune if necesssary with thinner washers.
I'll be fitting in a couple of weeks time I'd say.