Well, I went with the oil my buddy suggested. The buddy that helped me build my engine. I trust his judgement as I've seen him build several engines. He told me he broke his 440 in with brad penn 10-40. This was back in January . He tells me the other day that he's not sure if it was 10/40 or break on oil as he bought a lot of stuff including his oil from the same person. My question is will the pen 10-40 be sufficient for break in. I've already got 5 quarts in it. I'd planned on running for 15-20 minutes between 2000 and 3000 rpms then draining the oil and running 10-30 for 500 miles or so. I'd hate to waste the oil I've already got in it but if I have to, I have to.
