LS and LT Oil Diverter (Barbell)
The LS and Gen V LT Chevrolet small-block engines use an oil diverter that forces oil to pass through the engine oil filter. The oil is pumped from the pan, through the pump, past the diverter, through the oil filter, and finally to the parts of the engine requiring lubrication. This diverter is commonly referred to as the oil "barbell". It is installed in the rear of the block, behind the rear cover. The factory installed piece is plastic, and is known to let particles through (up to 250 microns) that would normally be filtered out by the oil filter (Most filters are 25 micron or less). The stem of the factory diverter is also large in diameter, which can potentially restrict some oil flow.
An inexpensive upgrade is an aluminium oil diverter. This piece is precision machined to fit the oil galley much tighter, and will not allow any oil to to pass by where it is not supposed to, potentially catching any particles and forcing them into the oil filter. It also has a thinner stem, which can only help to improve oil flow around the diverter. One of the best fitting diverters I have found can be found at https://www.saccitycorvette.com/. (Photo Credit)