I am rebuilding a 1966 289, The bottom end is stock, new crank bearings and polished crank. i would like to get a high flow oil pump, my concern is with the stock heads, the return holes for the oil to flow back to the bottom end are pretty small. can this cause problems when using a high flow oil pump? can you bore out the oil return holes in the stock heads and block so the oil can flow more back to the bottom end?

 

I had my engine rebuilt, stroked to 333ci, new crank, rods, pistons, alum. heads, 7qt. pan, windage tray, well beyond a stock rebuild and even with all that my builder advised to use a quality (Melling, etc.) oil pump that has been blueprinted (remove all flash, casting blemishes,etc.). He advised that the high volume and high pressure oil pumps are only needed on straight race only engines, normally with dry sump oil pumping sysems. On a standard engine they can actually move the oil too fast and 'wash' the bearings. If the oil moves too fast across the bearings it doesn't cool them enough or remove enough deposits was the description I've read also. I trust his judgement and his shop has competed in the Engine Masters challenge repeatedly.
My .02
Jon

 

As Jonk said, all the builders that I have spoken to, including the one that did my last motor, which was a monster, said do not use a high volume pump.

p.s. note the proper and over use of commas.