My sierra backplates don't seem to fit the Avon uprights properly. They don't want to sit flush when the holes are lined up. Am I making some sort of schoolboy error here ? They are from a 1.8 LX sierra if that helps.

mine was the same. I cut where it interference.
This teach us how bad tiger works

Hi,
The corners of the uprights must be grinded on two corners to fit the Sierra backplates .
I's quite easily done, the material of the upright is soft.
Look if there aren't any welding spots into the threads of the upright, I've had this problem when fitting them
cheers-JP

I grinded the brakes backplates, and after fitted I sealed it

My threads were terrible. I had to re-tap them all to clear them/finish cutting the threads. Another hour wasted doing something that shouldn't have been neccessary. Afterall, they weren't exactly the cheapest of components !

I'll have a grind at the weekend, just another Avon issue I suppose

make your own then

Mine also have to be grinded,
retapped due the spattering by welding the parts together.

But they are much cheaper (if you don't count the time which i spent on making)

I wish I had now that I've seen them. I want to get the rear end done though so took the quick option. I just hadn't expected to have to get the tap wrench out to sort the threads, followed by Tiger tool number 1 to make the backplates fit on.