HO52 gear swap preparations

[capev86]

i am hoping to change out the 4.57 gear for the 4.10 on saturday. i have a lot of the stuff ready to go but want you all to check my grocery list. is there a gasket for the third member to diff housing surface or do i just use rtv? i am planning to do both on the diff cover. they make a rebuild kit but the third member i am installing was reportedly serviced a year ago and i haven't had cause to susepect any bad bearings or such over the last several months of driving it. someone mentioned in an old thread about changing the cap when doing the swap. there is a cup and cone according to the list of part numbers i have.

what i have:
4.10 third member
napa diff cover gasket
permatex hi-temp silicone rtv
axle seals
royal purple 75w-90 gear oil