Wake up a 1968 318...

If you have leaking freeze plugs in the rear of the block, you either have to pull the engine or the transmission. The transmission is usually easier, but, if there are other steel freeze plugs in the engine, sometimes it's easier to pull the engine and replace all the plugs with brass ones. Pulling an engine in an A100/108 isn't all that easy though, so, if you can get to all the freeze plugs, I'd probably just leave the engine in the chassis and replace them best as I can. When you get a lower freeze plug knocked out, flush the block real good to get the rust and gunk out. I usually run a coat hanger inside the block to break up the sludge in the bottom of the block.