Originally posted by cdueced
Do all big blocks have a threaded hole in rear of the block next to the crank on the left side,3/8 or 1/2 plug.Looks like threaded hole is part of the engines lubrication system.
Generally, if my Geezer mind remembers, the oil plugs by the filter is a sign of a 4 bolt main block...............I will be corrected if I am wrong.