I ended up taking both casings off the RB box as i split the sr one today at work and threw it in our turbo wash and it came up sweet so i figured ill do both ends so it looks nice and then ill give it some good oil. thinkin redline shockproof. got new shaft seals and ill get a new front cover gasket and a shifter plate gasket. One thing i'm a bit suss on is what i believe is the reverse idler gear on the new [to me] rb box is a bix worn on the edge where it meshes so i might get it checked out but the rest of it looks sweet. i dropped the oil out of my other box and it was full of nice gold looking little shavings. its a shame the box doesn't want to come out of the car as easy as the new one came apart. oh well.