Need help with IDing brake calipers

[JNadal]

car is a 1970 911T
Calipers say ATE on them, I checked ebay and the "M" calipers available were in a box with UBD as the brand, but then I also saw Welmeister "S" calipers.
If anyone can post differences in the calipers available and the MFG's for 1970 that would help alot!

Thanks

[Jim Richards]

JNadal, the M calipers will have 3" spacing between it's mounting holes, the S calipers will be 3.5". A magnet will stick to the M calipers. The S calipers are aluminum, so a magnet will not stick to them. If a previous owner put A calipers on, they will have the 3.5" spacing but a magnet will stick to them.

[JNadal]

Thanks for the help!

[Shuie]

If you have the S calipers on the front, they will probably look a little like these

[Bill Verburg]

It might be worthwhile to look here

stok t has M front and rear calipers, they do have different sets of pistons though.

An A or S caliper will not bolt on to that strut