LOL. Not too much. A couple differences include that the ALH head....
-uses studs to fasten a cast aluminum valve cover down instead of the 3 mounting studs (similar to AAZ style) that attach the valve cover on the top of the 1z/AHU head...
- ALH head has a different shape of oil return from the head vs. the 1z/AHU heads that use the traditional hydraulic head style circular oil return found on hydraulic 8v engines...
-ALH head on the d side end of the cam and valve cover has the attachement point for the ALH's cam driven vac pump (vs. 1z/AHU that drives it off the int shaft/oil pump drive)
-Other than that...the heads are similar
Joe