Yes, if you claim to like thicker oils, you can use 10w-30 without your ILSAC stuff. A 10w-30 HDEO would be just fine. M1 0w-40 or GC 0w-40 would be absolutely fine, but a bit of a waste given your short intervals. Those engines aren't particularly hard on oil, and a 30 grade of some sort, even with elevated HTHS, is pretty much ideal.