any 52 chevy guys out there? rear end question? common rear ends

Sup..well i have a 52 chevy deluxe and i'll be running a 350/th350 trans on it..currentlly i have a 57 rear end, and will be purchasing rear end kit from RB's Auto..is it easy to center the rear end?

as right now i have housing sitting on my leaf springs..i know i have to torch off the stock perches and weld on the new ones...do i need to put on the carrier back on the rear end housing and do i have to have my engine and trans in it?