Hi, is it an aluminum filled epoxy? Probably, I have used devcon steel filled epoxy, it is much like jb weld. I remember looking at devcon's literature and they had epoxies filled with all sorts of different metals, stainless steel, titanium, and some others. I think maybe their jb weld equivalent was called liquid steel but in a larger package the same product was called steel putty.
JB weld may do the trick for you, it is durable stuff and I think it would take the heat ok. Sometimes it helps to warm it with a hairdryer, makes it thinner and thus will seep into crevices, also heat will speed up the cure. I have used it with bits of fiberglass cloth with excellent results.
However, I think the radiator trade uses some sort of glue to effect aluminum radiator repairs, maybe look there.
Yeh it is the aluminum filled epoxy. I talked to a mechanic and he said he has used it gearbox repairs and it is quiet strong and should take the heat. So im thinking when i get that far im going to give it a go and save a whole heap of money in the process