Just a thought- - - -sleeving the block and then gun-drilling the oil passage through the lifter bores might be a good way to substitute Ford/AMC/MOPAR hydraulic lifters for the notoriously unreliable Chevy hydraulic lifters in the late model blocks with the hydraulic lifter option available. All of them have the same .904" diameter. Custom pushrods would be required.
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!