two bolt BB vs four bolt

[Zman1969]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VintageMusclecar</div><div class="ubbcode-body">The later blocks (I have a &quot;445&quot; block) aren't drilled for the large hole since the trucks they came in usually had an aux. oil cooler adapter sandwiched in between the block and the oil filter. There was no longer a need to drill the block for the larger fitting. </div></div> any idea what year this started?