Not bad. The OP said it cleaned off 1/3 of the sludge in some areas. Don't forget that 'oil flow' areas are the most important. You're not going to get all crud off everywhere where oil doesn't have regular flow.
BTW, I don't care for or recommend AutoRx. But, you can't argue with:
As you can see there is still a lot of cleaning to go, but I would say the Auto RX cleaned at least 1/3 the sludge. It seams to have worked best on the lower portion of the head where there is the most oil flow. In the last pic, you can actually see some areas of clean bare metal.
All and all, I am happy with the results.
I do recommend GF5/SN oils. Synthetic isn't a must for your engine but is an option if in your budget.
I do recommend avoiding extended oil change intervals. I wouldn't go more than 3k-5k OCIs, and as always top off as needed for any consumption.
At this point, you'll get plenty of cleaning with GF5/SN oils.
Nothing wrong with a low dose of Kreen IF YOU HAVE IT. Instead of using 16 ounces, use 1 ounce per quart. And, it won't break off any chunks. Even kerosene doesn't. Engine flushes breaking off chunks is one of the Autorx clan's scare tactics.
What I would try is a 3k run with Lubegard Bio/tech Engine Protectant.
Lubegard
And, I would try Zmax for another 3k run. I noticed it has some slow surface cleaning ability.
Zmax