I forgot: not all clutch covers will bolt onto all Cleveland flywheels. That's one reason why aftermarket flywheels (steel and aluminum) have several clutch bolt patterns drilled into them. Some that are the same pattern use different thread sizes & lengths, further complicating things for DIY-ers. Finally, a lot of OEM Ford flywheels 289 to big block will bolt onto Ford V-8 crankshafts but many are drilled for 10-1/2" OD clutches, not 11" as used in the 351-C, 400, 429 & 460 engines.
And no- you cannot predictably redrill and tap your own flywheel. Just a few thousandths off will have your engine shaking like a wet dog at 6000 rpms. Just before something lets go like a grenade in your bellhousing! That doesn't even touch on the strength of OEM gray-iron flywheels when home-modified for use above stock Cleveland redline of 6000. I'm all for DIY, but not with flywheels! I used to have photos of that Texas Pantera that exploded a flywheel (drag-race or road race?) and it nearly severed the rear subframe & blew a tire, also wrecking a rear fender & decklid.