Hi all just a question in relation to the two what looks like oil return one way check valves in my EL block. Do people normally remove them or keep in place i noticed my EB block doesn't have them.
They are located in the oil feed holes to the cylinder head at tghe top of block.

Thanks

The plugs in the oil return holes were installed to increase oil pressure for the hydraulic lifters. On startup, the lifters often rattle. Blocking them off, will reduce that (especially in cold weather). The engine reconditioner, that I use, gave me 3 to install during my engine rebuild.