8 3/4 guru need your help

like I said in an other treads I just bought a 727 with a transbrake in it with a 8'' 5000 rpm stall

now I spoke to a friend and he told me my 83/4 will never gonna be able to hold with my set up could it be true I alwais love the 8 3/4 dif
and have 3 gears that goes with it

I already have bears axles in
what do you suggest to make it stronger

thanks Bob