Disc Brakes question

It depends, because there are two different spindles for the 10” drums. ‘68-72 the 10” drum spindles used the same small upper ball joints as the 9” drum spindles. But in ‘73 the 10” drum spindles started using the same large upper ball joints as the 73+ disk brakes.

So, it depends on which spindles that kit is designed to use. What’s the part number of the kit?
thanks for your information, the kit I have is SSBC A153-1 SSBC USA Drum to Disc Brake Conversion Kits , my mechanic called SSBC and they told him that they are designed for 10 inch front brakes spindles