OK an update. Got some time to work on it today and I got the vac pump installed.
First, had to remove the fan. Hub locker and a fan wrench made this easy.
Second, removed the bracket from the vac pump:
Third, installed the pump which takes the 3 bolts that held it to the bracket. They now screw into holes on the alternator bracket.
Fourth, run to NAPA to get a longer belt. The 101 from RockAuto listed as for the stock config on this truck was basically the same length as the stretched out 100 from the ATT install. I ended up with 1015 (actual length 102 1/8") and all is good.
If I eliminated the learning curve part, this job would be less than 30 minutes. Big thanks to Paveltolz for the install diagram on the Vac Pump.
Tomorrow I put back the GM 5 turbo and hook up the vac lines. Then I schedule myself an appointment with the Smog Referee. I will not install a muffler, just the catalytic converter. I think the referee will know that a muffler has nothing to do with smog. I feel like I have to be the only 6.5 that's ever gone back from an ATT to a GM 5. Fortunately, that set-up will be very short lived.
P.S. When you think you've got it bad with your vehicle, there's always someone who's got it worse. While waiting in line at NAPA, there was a guy in front of me comparing his hub assembly to a new hub rotor assembly. This was from a Dodge and the rotor attached to the hub from the back using the wheel studs, much like the GM set-up on our 6.5 trucks and Suburbans. Only problem, the entire brake surface portion of the rotor had sheared off its hub. I asked him how it happened and he mumbled something about the caliper locking up. Anyway, he didn't believe the NAPA guy that the rotor (hub) separated from the wheel hub, so I jumped in and showed him. So the guy leaves and I'm getting serviced for a longer serp belt. A few minutes passed and I blurted out "how the **** do you shear off the rotor from its hub?" Every guy behind the counter started smiling and snickering like Precious the Cartoon dog. Then the guy servicing me pulls out his trophy, a brake brake from a F-350, only the brake pad was long gone and the metal was just chewed away. He said they guy insisted that the brakes has just started to make noise 2 days prior. Right.