I was at a Mopar car club meeting last night and I asked this question. One dude said his best time was 45 minutes. I called bullshit on that.
Come on, man....be realistic. Even with an automatic car if you're really fast, have air tools or cordless stuff, that is draining and removing a radiator, disconnecting a torque converter and bell housing, starter, all front end engine accessories, motor mount bolts, disconnecting all wiring, maybe unbolting the exhaust manifolds from the heads, disconnecting the fuel line, KD linkage, throttle cable and vacuum line to the brake booster, removing the engine and then reversing ALL of that while also getting it started up and driving out.
There is no way you are 45 minutes fast with a new cam.
No way you'd do it even with an engine with the distributor in place and already set to proper timing, full of oil and oil filter in place.
Now if this were a VW Beetle, maybe.....