Okay....so the tube is meant to supply oil to the front main bearing by cutting off the leaks at the lifters.
After the tube is installed you drill a passage in the tube at the front of the block directing the oil into the oil passage that feeds the main bearings, correct?
Just making sure we are on the same page.
Charles Sanborn also blocked the lifter valley above the camshaft to allow the splash coming from the crank to lube the cam and lifters. He drilled and tapped the block to accept aluminum block off plates that covered those oval holes in the block.
Has anybody used the aftermarket block off plates that I occasionally see offered ?