1964 Valiant Single to Dual Master Swap Question

The MC is a power brake unit but will work fine with the rod. They use the clip to hold the piston in and the same rubber ring to secure the rod. Use a new rubber ring on the tip which might not have come with the unit but should be available.
If you want to use the boot/spring retainer you would have to drill and tap the 1/4-20 holes. (carefully) I just did this last weekend.