Going to replace the rear main oil seal on the 350 in my 70 Chevy. I plan to replace the seal with the motor in the car. Can anyone tell me how hard it is to push the top half of the seal out?

You need a Sneaky Pete. http://www.sjdiscounttools.com/kdt492.html

Never used one myself, but the name stuck in my head...

That has the rubber seal with a steel core. Will slide out very easily - and the new one will slip in easily also. New one should be oiled up when you slide it in.

You can use a small punch to drive on the metal core of the old seal to get it started. Then use pliers of some type and work it out from the other side. Use care to not nick the crank, and use a light coat of sealer on the main cap near the seal when going back together.

Thanks guy's was told I might have to move the transmission back.

There should be no reason to move the transmission.

Had figured I didn't need to move trans, just wanted to make sure before I started, thanks.

Your biggest challenge with this job will be getting the oil pan off. You will need to remove the dust cover on the transmission to get the oil pan off, loosen the motor mounts and remove the y-pipe if it has single exhaust. Don

Replaced the seal with no leaks, job was a breeze. Just backed off the bolts on the mains except the front one. Seal just pushed out.