as TJP mentioned, one has to be careful of the surrounding area of the casting or item when deciding what repair insert to use.
if i remember correctly, [there is that "remember" thing again ] the airplane spec for a bolt hole to edge ratio is 2 to 1.
in other words, if you are using a 1/4" fastener, the hole edge "should" be 1/2" away from the edge of the item.
we all know that there is a lot of things on a vehicle that are fastened not following that spec.
just look close and decide for yourself if you have enough meat to drill the required oversized hole necessary for the [chosen] repair insert to work without compromising the item at hand.

and Sniper is right. use the new reusable factory gasket for the [904]A500/A518[727] to help with gasket leaks.
however, it was also mentioned by bee1971 : "And 99% of 727 transmission pan gasket leaks are not the transmission pan gasket"

look at cooler lines and fittings for cracks, as well as the reverse band servo lever pin area. [where the pin is visible where the tailshaft housing bolts to the rear of the case. the o-ring[s] used there can wear out, causing a leak.