Reply to "Crank end seal advise please"

Kristian's right, Johnny- you can simply drop the front of the pan down a few inches without actually removing it, remove the harmonic balancer for access and replace the front pan seal from the passenger seat. The two ends up in the corners where the pan, block and seal all come together are the tricky areas to get sealed but it can successfully be done w/engine in situ.
THe front CRANK seal can also be R & R-ed with engine in place, without disturbing the pan, as long as no one has accidently installed a 351-W front crank seal. Coincidently, the Windsor front crank seal will also fit the Cleveland engine, but it lacks the 351-C's front flange for easy R & R. So in that case the whole front plate must be removed to get at the Windsor seal. With a 351-C seal, wedging a flat screwdriver between the bad seal's flange and the front plate will easily pop it out.