727 Time to rebuild

It's always all or nothing is what I usually hear. Either a "complete overhaul" which doesn't really mean anything, or not even touch it. I can't imagine not checking the front drums with a trans out of the car and the vb removed. People do valve jobs on motors and replace timing chains; even oil pumps, all which are a lot harder than checking front drums, but they don't decide to just rebuild the whole motor cuz the timing chain is loose or it has a burnt valve. I don't get it. It would cost a front gasket and a o-ring.