I was able to R&R the oil pan on my 49 216, in truck, without any clearance problems. It weighs more than you think but I done it laying on my back underneath. I'm unsure if the 42 has the same clearances.
If you haven't dropped the pan before it is a good time to do so and give the innards a good look-see. Plastigauging the bearings will tell you how much life you have left in it. May even still have some main bearing shims you could remove to gain more oil pressure.
All that said, fishing around with a long handles magnet and/or one of those mini endoscopes "may" save you a lot of work.
Good luck
Dave
