454 Leaking lots of oil ?'s

[1968SWBBigBlock]

I like your idea of pulling it.
I have changed my a couple of times with the motor still in the truck.
With my old Milodon pan I did not have to jack up the motor - my Moroso pan is a different story.
I take out the transmission bolts on the crossmemeber and the tranny mount - pull the bolts on the engine mounts and jack up the motor as high as I can.
Once you drop the pan you may have to rotate the crank to get the front counter weight up into the block - this will let the pan pull out.
I like the one piece oil pan gaskets - Mr Gasket brand is a favorote over the fel pro but I would use both.
The rear main seal is pretty stright forward - pull the rear main cap - this half of the seal you can pull out by hand - the seal in the block can be a bear - espcially if it is old.
Use care since you do not want to scratch the crank or seal area
It may help to use the lower old seal to push out the old uppper seal
I always put a small amount of assembly lube onto the seal lip so it is not dry at start up.
When I install the seals I also set them up so instead of the seal split being at 9 and 3 oclock I shoot for 8 and 2 olclock - that makes the split lines fall inside the block and inside your rear main cap. Helps keep them from leaking.
torque down your rear main cap and clean everything and reassemble.