FWIW, I don't like Alclad black base because it never seemed to dry fully for me. Even after a week.
I build the model, prime with Gunze Mr. Surfacer 1500, then spray Tamiya X-1 gloss black on it. I thin it with the lacquer thinner. On my recent F-86, I let it sit for two days on the initial coat, but I actually came back and redid the black. I layed the black down on an evening, then came back the next day at lunch and sprayed Alclad Airframe Aluminum.
My go-to clear for Alclad is their Aqua Gloss, which is an acrylic and must be cleaned with water (or it will harden in your airbrush and be a HUGE mess. According to the bottle, you can spray it 6 hours after a metal coat is layed down. I shot mine in about 4.5 hours, but I also bring my builds inside and let them dry in a pretty non-humid, 72-degree house.
Once the Aqua Gloss is dry, I add decals, and then do another coat of Aqua Gloss before my panel line washes.
I have not gotten cracked paint when flipping between Tamiya, Alclad Lacquer and Aqua Gloss. I HAVE gotten problems when I used Alclad Duraluminum directly over Airframe Aluminum on another project. It had been about 36 hours since the airframe went down, and the solvent in the Duraluminum attacked it.
I hope that helps a little. It has worked for me on two builds so far.
A note on clears: I LOVE Alclad's Gloss Klear Kote on everything but Alclad. As it's a lacquer, it uses the same solvent as their paints, and I have found that it changes the colors. If you lay decals down on the metal without clearing it first, then clear it, it's basically like decal carrier film hi-liter.
Anyway, here is the F-86 I mentioned:
-BD-