Rear end swap

Ok, well iam new on stang net, but i wanna know what you guys think about this..
I have a 96 Gt stang, and my friend has a 98. I had 3.73's gears and he had 4.10's.. My motor is a faster rev-ing motor to begin with and we talked about it and i needed to get some upper and lower control arms. He already had some and bought new ones from Maximum Motorsports so we can do this swap. Now I have ABS and he doesnt. So the plan was to swap over ever part we could to make this work. The axles had to be swaped, as did the brake dust shield, the control arms, diff cover plates, fluid, and did this in one day. Well 7 hours to be more like it. With a half hour lunch and 2 15min breaks. Now iam not a ford tech and niether is he. He does body work for a living, and iam a Maintenance tech at a college.... Never done a rear end swap either.. It was the 1st time either one has done anything like this.. Now a local shop said they could do this in 3 hours.. or less.. Now tell me if that sounds at all possible...
We had 2 jack the cars up
Wheels off
Rear brakes off
Disconect Ebrake lines
drop sway bar
control arm bolts
pull both rear ends
swap over diff cover and axles
put everything back together... On 2 cars mind you...
Let me know what you think.. thanks lol

Well we had both rear ends dropped in 45min. But it was swaping over the parts... the reason for swapping the parts was for the gears. I wanted to 4.10's and he wanted the 3.73's. Other wise yea it would be so much faster. Plus we had to welding on the upper control arms due to hard driving tearing the holes bigger than stock. So we welded a washer to fix the slop...