anaerobic sealer is primarily used for aluminum parts. i dont recommend it on aluminum to steel however it can be used. i usually use fuji bond or toyota bond for subaru oil pans or use grey rtv and use a heat gun just be sure to not get it extremely hot. grey will usually set up relatively fast even in cold weather. its the black and orange rtv that takes forever
It will cure fine, once you apply pressure from tightening the bolts that will speed it up. I would use RTV, black like toyota fipg or permatex. I have some grey fujibond and when I compared it and permatex the permatex dried tougher. It was easier to rip the test bead of fujibond. I sealed my ej20k case halves with permatex grey and it never leaked or seeped. The important thing is to make sure both surfaces are bone dry and have ZERO oil residue. Use something like mek or acetone to clean both surfaces thoroughly with a super clean cloth.
Almost forgot to update, this morning when I got home from work I checked the RTV ultra gray on the pan and it working the rest of the week is going to be a little bit colder but by next week it should be cured enough that I can put oil in the pan.