Something that JohnRR hipped me to!: that a blocks' lifter bores are at an angle and the lobes/lifters conform to that and another block will likely not have the same exact angle & reusing them on another block can cause wear problems. As said I'd get a Summitt cam/lifter kit (they're cheap) & cut some diagonal grooves in the old cam journals with a hacksaw blade & use it to fit a new cam if it dont turn easy (likely it will here with used cam bearings but for the future) and keep several of the hyd lifters and JBweld the cup solid .015-.020 (whatever your preferred preload might be) below the snap ring & use em when dialing in a new cam