The disc brake calipers will probably need more volume than the original equipment master cylinder can provide, plus discs usually need a power booster to function properly. Pairing up a disc brake with Huck fronts would be interesting, for sure!

I'd suggest working up a "dual diagonal" setup, where one rear disc and one front drum brake on the opposite corner of the vehicle is operated by each chamber of a dual-outlet master cylinder. That should equalize the fluid volume from each chamber and might avoid having a bad mismatch from one portion of the master cylinder to the other.
Jerry

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