LA blocks

Only the first couple years of the Magnum block has the hole drilled for rocker shaft oiling. Run the magnum with their heads and you’re gonna be oiling through the push rods.

If you’re using aftermarket heads, most use oiling through the head.
Your course can use oiling through the push rods on the LA heads but you need the proper rockers and the good ones to run about seven $800 for a set.