The important things are to get the stack clearance into spec and to presoak those discs. I believe the thicker waffle discs can take more abuse, so they always go into the hi-drum.
I would not put the pistons into the freezer with the lip seals already on. I've never had to resort to that. But if the lip seals are frozen hard, well,that won't work.
Just use plenty of silicon O-ring lube on the lead in chamfers. You don't need to slather it in there, but make sure every sq mm of the chamfer has at least one molecule of grease on it. Then a matching smear on the lip seals.Then straight down she goes.It will practically fall in there.
But if you accidentally fold over the lip seal(it's always the outer), I have a trick.Firstly; a new lip seal can take quite a beating.As long as it hasn't split, it's good to go.Then, there is enough room in there to bias the install. What I mean is, when it is correctly installed, it is possible to move the piston from side to side, compressing the lips into the bores. Knowing this, You can start the outer lip seal by holding the piston at a very slight angle. Ima thinking 2*to 3* or so. Then push the piston hard over into the bore, and drop the other side down, gently, wiggling the high side back and forth, but always keeping the piston hard over on the low side.The final inch can be tricky, and sometimes needs help.I only use this method if I have previously folded the lip. And I put the folded part on the down side, and, in first.I never fold the lips any more!
But really, with the silicon lube, the things practically assemble themselves.
