These brakes are going to kill me. I knew there could be issues with wheels fitting over them, but I went for them anyway...albeit used
Some of the parts that came with them needed replacing, bleed screws, bolts washers etc. So I ordered the correct parts after verifying with MiniSpares via email. The bleed screws were still incorrect and not the correct M10 version. Sorted that out with Simon at MS. Checked fitment with hubs off the car on a spare set of John Brown Wheels alloy Cooper replicas. Tested all four wheels torqued with both hubs and removed the ridge on the calipers as needed to fit all four wheels. I knew the weights would need to go on the outside, but not a problem for me, although they have not been balanced yet.
Get everything back together and the slightly older set of the same wheels is a very slightly different casting and won't fit without more "adjustment ".
Gotta love Minis and Mini suppliers
I have minisport 4 pot calipers and had zero issues on my 10s. They stop great too. This is on my lightened blue mini with rear disc. This mini really stops!
I've only had experience with the MiniSport ones on Don's Pup, they bolted right up and worked perfectly - way better than the Wilwoods he had on there before.
So, what 4 pots are these? MiniSpare's version?
Are you trying to use them with ventilated discs?
I know some of the JBW sets come in versions meant specifically for disk brakes and some specifically for drum brakes. The sets will look identical, but have different part numbers. The disk brake versions will fit over both disks and drums, but the drum brake versions will only fit with drum brakes.
Perhaps your older set are a drum brake version?
On my Mk2, I have KAD 4pot alloy calipers with 8.4" ventilated rotors cut down to 7.9". They fit fine inside 6x10" Revolutions. The stick-on weights are mounted on the inside and are positioned inboard in order to clear the calipers.