Here are some pictures to prove my point. Take it for what you will. LeMans850i can confirm when he receives his rotors.
Note the manufacturers dimensions above
Here is the stock front rotor from my ‘74.
Here is the 125-61053 after I turned the OD down.
Here is the stock rotor hub diameter.
Here is the hub diameter of the 125.61053. Note it is oversized compared to the original. The rotors will be stud centric.
Here I measure the stud hole on the 125-61053 after it has been machined to fit the stock wheel stud with a bore gage.
Here is the bore gage in the caliper.
Here is the factory stud shoulder measurement.
From these pictures you can see that I had to take 5mm off of the OD of the rotor. Without this the rotor dragged on the under side of the caliper. And, the factory stud will not register into the rotor unless the stud holes are opened up to 17mm.
Another issue is the thickness of the rotor flange. The stock flange is 9.2mm while the 125-61053 flange measures 7.75mm. The factory studs require a 1.5mm washer under them so that they do not protrude too far through the axle flange. If they do you could have an issue tightening your wheels because your lug nuts could run out of thread and bottom out.
I put a lot of time into this. If you don’t believe me, by all means feel free to try this yourself.
Steve
