Someone mentioned the possibility of sleeving the lifter bores to accomodate hydraulic lifters for a different engine (MOPAR, maybe?) It shouldn't be too difficult to find a more reliable lifter that could be retro-fitted to the stovebolt block. As long as the oil fill hole is in about the right location, the lifter doesn't care what kind of engine it's installed into.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!