you are running a swapped setup with axles that are welded - what they will do is weld the shaft to the inner spider - it can then take good load but everytime you need to replace the boots you need to grind it off and reweld it.
No-one can guarantee you what you want, I have broken mazda RX7 factory rear axles, busted a supra differential behing an automatic trans (that supra was pulling 600 hp - had to get a 4000 rpm stall converter for it to survive)
You should also look into solid engine mounts for drag racing - solid as in SOLID METAL TO THE FRAME or using 90 shore urethane solid mounts to reduce judder shock on the axles.