You would have to come up with a way to hold all of the lifters to the top of their bores. Its been done with sightly modified wooden clothes pins. Cutting a curve in the faces to more completly clip onto the lifter. Its possible some of the more modern office clips would work. Problem is if you drop one its nearly impossible to get it back in with the crank, rods and cam in the way. If you manage to hole them up then you will need to pull the radiator and possible the grill to get the cam out.
You may be able to rent or borrow a cam bearing installer from one of the local parts stores. If the cam and bearings are bad you need to remove them all including the last one in the block that is behind a freeze plug in the back of the block above the crankshaft. If reuseable you would need to get the tool into the center bearing and rotate it to line up with the holes (or groove). You would probably need to remove the front cam bearing to get to the center one or get it out.
This is by all means not a simple job and if the oil flow problem has been there for a long time there may be other bearing damage. I would at least pull a couple of main caps and rod caps to check the condition of those bearings.
The add on oil system taps off one of the oil galleys (plugs in line with the oil pressure gauge fitting) and carries oil under pressure from there to a Y fitting that carries oil into the rocker covers. The better ones have a hollow valve cover retaining stud that allows the oil to enter the rocker shafts and oil the rockers per original design. Easily done with the engine in the car and would be a temporary fix for your problem.
Chuck


Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.


MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire