kz400 steel clutch plate question (direction)

I took the plunge today, and got going on replacing the clutch on my 74 kz400. I had been experiencing really high rpms in 5th gear. I was getting 8000 rpms at 65-70 mph. So I replaced the clutch cable which helped immensely with the ease of shifting and finding neutral (i was having trouble getting the bike into neutral when it was running), with the new clutch cable those problems have gone away. However the High rpms in 5th was still an issue and many tries at making the push rod adjustment, I went ahead and decided to replace the friction plates. With the engine cover off one thing jumped out at me, and that was the amount of slack in the primary chain. The service limit for the primary chain slack is 20mm and I have a lot more than that. I'm not sure If this would cause slippage but I went ahead and ebayed a new used primary chain that is hopefully in better condition that mine was.
I also checked the thickness of my friction plates and have come to find out they are not to bad. they are not yet at the service limit but are fractions of mm's away. So I'm still not sure if that was causing my slippage. I also checked the clutch spring measurements and again I am not yet at the service limit (these are a couple of mm's away from the service limit), so again I don't think these are the issue. It boils down to this, I'm going to replace the friction plates and primary chain and see if it gets any better. If it doesn't I fear it might be something like the clutch release mechanism.
As for my question, I read some thread about how these steel clutch plates have a beveled (rounded) side and a side thats not. Once I got the clutch apart I was able to see what the guy was talking about. Does the rounded/smooth side of the plate go toward to engine or facing out. I did note when taking it apart that the PO had the steel plate rounded side in different directions. Some were facing in some were out. Maybe this was how the factory intended, but I'm not sure. Does anyone know which way these steel plates face? If I could find the thread again I would have my answer... but I can't seem to locate it. I would have never thought about this unless I had read about it...evidently a guy put his steel plates facing the wrong way and the clutch would not function properly. So I need to know before putting this back together

I don't think it matters which way the rounded side faces because both sides of the steel plates engage the friction plates.

What could contribute to the slippage is the use of improper oil. What motor oil are you using in the bike? Ed

I was told to put the rounded side out.

Thanks for the replies. Ed, Initially I did use the wrong kind of oil... I used car oil 10w-40. I have read your threads about proper oils..those have been very helpful. As soon as i realized my mistake I did change the oil to castro 4 stroke motorcycle oil which is what I intend to keep using... it does have the JASO rating on them (which is what I want correct?). Anyway, could the wrong oil I put in at first have contaminated my friction plates to the point that they need to be replaced? Well, I'm doing it reguardless I just hope something I do solves my High RPM issue. Maybe just a better push rod adjustment would have done the trick. But I tried that many times and get the same results. I was scared to do this clutch repair, but in the end it turns out not to be that hard to do. The hardest thing for me is getting off the engine covers... Seems like every screw is stripped. I've made sure to purchase allen heads for the reassembly .

The wrong oil may have affected the friction plates. Using JASO-MA compliant oil will prevent the new plates from being coated with the "friction modifiers" found inmost car oils. When you put everything back together be sure to apply the correct amount of torque (as defined in the Kawasaki Service Manual) to the clutch springs. Also, it's a good idea to apply a liberal coat of the correct engine oil to the steel and friction plates before installing. Ed