Ok I just got my block back from the machine shop, and I was planning to start cleaning it and the rotating assy this weekend so I can begin the shortblock assembly.

Anyway...I was told by someone local that I should smooth out and slightly enlarge the oil drainback holes in the corners of the lifter valley, and also tap the little vent holes that are just to the inside of each pair of lifter bores and put extensions on them. Is this true, or is this a practice that is only really necessary on older small blocks with flat-tappet cams? And if it is true, where do I get the little extensions I need, and does anyone have pics of this done?

If it is true, then I need to do all this before I clean my block...

Here's of couple of pics of my block for reference:

 

Ya don't need the extensions but ya do need to enlarge the front and rear holes. Just imagine what it would take to make the oil flow better back to the pan and grind accordingly.

 

Ok, will do. Thanks

 

You also have cam bearings in there. I have some pics of what you need to do, but you will need to take out the cam bearings and clean the block and put new bearings in if you do all that grinding.

Bret