I'm having trouble deciding what the thread sizes are on the cortina uprights.
I reckon the caliper mounts are m12 am i right as the bolt seems to bottom out after about 3/8 of an inch.
Maybe i just need to run a tap through them but I want to be sure first.

The cortina uprights are all metric threads. IIRC the caliper bolts are M12 8.8 grade. Disc to hub bolts are M8 10.8 grade.

The part that the caliper bolt goes into is only about 1/2" thick, and the bolts dont go all the way through so I should think that the last few threads are full of crap and rust. Run a tap through them to clean them out.

David

Cheers mate will borrow one from work tommorrw or even Monday