i did mine without the jackstands(did not have one)maybe that's why it took me almost 2hrs? but i did it myself and it was easy. only hard part was taking the old cat off. it was like the bolts melted!:D
i did mine and it took me about1 and half an hr. now if you have someone else help you it should be less time. ohh and just so you know they charge about 250$$ to put it in(at a muffler shop)