If it’s any help, I used brad penn breakin oil for my most recent 261. It’s now called penn grade. My 261 is very modified. 59 block, 302 gmc Rods, cut down 302 Bearings, venolia forged pop up pistons, Schneider solid lift cam with 492 lift, 280 seat pressure, big valves, porting, polishing, smith brothers push rods and rocker adjusters, all kinds of stuff. The motor broke in perfectly with the brad penn breakin oil and has run like a top notwithstanding my sometimes hard driving, lol. So, I prefer it and will use it on the next 235 motor that is in the works.
For many years I used Kendell oil (Bradford, PA) and a container of GM EOS but the EOS sold today is a different formula. As below, you can use oil plus a ZDDP package but the break in oil is still different in that it has an enhanced additive package just for the initial start up. One of the reasons I prefer the BrandPenn/Penn Grade is that it is refined at the same refinery that the old line Kendal oils were refined at and the oil is still the clingy green stuff that served me well over the years. PA crude stock which I am told is a better grade lubricant, a partial synthetic package, a break in additive, and no issues with break in. Fourth motor on the stuff. Also, last spring when I took the valve cover off for a spring adjustment, stuff was still on the rocker arms and springs so I thought that was a pretty good sign.
Others have their favorites, in the end it may not matter, but I go with what has worked for me anyhow.
Last edited by Dragsix; 03/01/2018 9:05 PM.
