" Poll time"

Hey guys I have had bad clutch chatter after rebuilt engine (68 Cuda 383 4 speed) and new mcleod clutch kit and resurfaced flywheel. It looks like my rear main seal is leaking a bit and maybe slinging oil on my clutch. So anyway I have decided to pull clutch and inspect rear main seal.
My question is should I pull engine and 4 speed or leave engine in car and only pull gearbox and clutch?( A couple of years ago i replaced a rearmain seal on a 440, with tranny pulled and i was able to simply push out old seal and install new seal with just removing seal cap). I will be working with car on stands in garage. Thanks