Hey mate,
Ive been alloy brazing for 15 years. Most of the seemingly simple products that claim to work aren't that good. Ive tried most of them, but nothing comes close to the flux I use. Brazing of alloy, especially this size and thickness requires heat, and a lot of it. Brazing works just under melting point of the metal to be brazed, so the metal must be heated to a constant temperature during the duration of the job. In my opinion its not a viable solution as it would need to be stripped. Also you dont know the composition of the metal. You dont get a second chance with brazing as in the blink of an eye it can turn to powder...this has one of smallest windows of repair of any metal. Anyway if you choose this path, do your research as to the requirements and conditions from the seller.
In my tested opinion nothing brazes better than 16% silicon alloy rod and allubraze flux.
There is an alloy epoxy we use that is stronger than the alloy it bonds to at ambient temps, but when combined with high engine temperatures it will become pliable and fail.
A bracket as Aus says may be an option or even making a bracket and nut a
taping it into the casing and sealing with high temp retaining compound.
See how you go good luck:)
