I don't know if i would recommend those two together. A long time ago, I did a very high dose of Ketamine (~130mg) and stupidly let a friend, who did not know that I had just taken K, give me an unknown amount of 6-APB. My buddie accidently spilled almost the whole bag into a small cup of juice and it was a LOT, probably enough for 5-6 people to have a amazing experience. I was unfamiliar with how much that actually was and so i thought little of it and took it. It was VERY dangerous decision i made. It took about 20 min to kick in, but it wasn't a slow or gradual onset either. In the period of a minute and a half, I went from pretty much sober to full blow OBE (outer body experience). It started by seeing small specks of light of all different colors starting to appear (I was driving at this point because I was completely sober up until this point). I pretty much knew the second I started seeing all these lights and trails coming off them i was in deep shit and pulled over and got out of the car. Sat down on the sidewalk and I started to have extremely vivid hallucinations and my vision became very fractal and trail like. It was pretty intense and had got so intense so fast that it kinda worried me for a moment (thankfully I had a buddie there with me to help me realize I was just trippin really hard and i was actually fine). So I got back in the can and at that point pretty much had to close my eyes cause the visuals were so intense I couldn't even see what I was actually looking at anymore. And thats about it, I don't remember much else after that point except for my buddie just telling me a story on the way back home to guide my experience in a positive way. I peaked for like 4 hours which was just an OBE. After about 4 hours i started to come back and up until a day and a half later, everything still seemed surreal. As overwhelmingly intense as it was, it was actually quite spiritual and it changed my life in a good way. Pretty much was rollin balls in a K-hole is what it was. I've experienced some VERY intense trips before BUT this by far took the cake. I'm pretty sure i could have died that night had i been inexperienced with OBE's and intense trips like that and not had a close friend who knew how to guide somebody in that state. Like i said before, I did this a long time ago and in my honest opinion, a extremely dangerous thing i did that night. I say this as kind of a learning experience for something stupid i once did a long time ago of combining these two together.