Harland Sharp have a very good reputation. they are 100% USA made - not some Chinese copy re-branded to look like locally made (like many UK sourced steel connecting rods).

The only issue I had with these rocker arms was the height of the spacer.
One may have to remove some material from the bottom - or add a spacer with a non adjustable hydraulic lifter.
Solid lifter should not need to worry - as one can adjust the lifter length.

There were several variations with rocker arm pedestal heights over the years (in Canada and USA) So one must measure when doing a cylinder head assembly. Never assume any non-factory part is perfect. Just like measuring bearing clearances - don't trust anyone.