There is a good reason that your '53 full pressure 235 was "leaking pretty bad" with that style of main seal.
That engine came with shimmed main bearings. The lip seals will not work on that engine. They cannot be easily trimmed to fit without a gap for oil to spew.
Once GM tidied up their block machining routine so that shims were no longer necessary (1955?), the 2 piece lip seal became a nice option in place of the rope seal.
