Changing crankshaft bearings with the engine in the car.

the gargantuan pain in all nine assholes of laying on the ground with **** dripping and dropping on your face while cussing and fussing on this job aside... what happens when you're done and (insert sing-songy voice) the oil pressure's still low?

while it's likely just the bearings are beat down, the possibility does exist that the crank could be pooched as well.

or maybe the oil pump is waxed ***...

i say throw some 50 weight at 'er and let it rip, see what time it is.

but if i'm doing mains, i'm doing rods-- in for a penny, in for a pound. what's another few hrs to yoink a motor at that point for the ease of working standing up.