These are the original Vandervell “V” race main bearings for the Oldsmobile engine. The “V” main bearing is commonly used in the high performance Chevrolet engine builds. The benefits of the “V” main bearing is that it can with stand much higher loads than the “P” main bearing can. Were the “P” bearing will flake, loose crush and seize in the higher HP applications, the “V” bearing will not. This is a tri-metal indium over lay main bearing. I use them in all my engine builds. These race bearings come in Std, .010 and .020 under. Big block Olds bearings in standard shown here. Please specify when ordering .010 or .020 under.