Where should I mount my bindings

Center mount them bad boys.

make sure to say True center at the shop because some manufacturers will have recommended "park center mount", which for my head skis they were like 6 cm back

i would mount at recommended point, or between recommended and center. i don't think the advantages of center mount outweigh the disadvantages unless you literally ski switch >50% of the time and/or only ski park and nothing else. mounting up is nice but it means youre higher up on the sidecut of the ski so they won't turn quite the same way they are designed to

that said, you can't go wrong either way and it's not going to matter a ton. and yes, if you decide on center, make sure to be very clear that you want them mounted at TRUE CENTER, and better yet, mark if for the shop. tons of people have had miscommunications on that because most shop employees are not used to true center mounts

Are they dedicated park skis or all mountain and park?

I'm not sure if the mount points are the same on the 86 as the 96 but the 96 has two recommended points, -2.5, and -5. I'd mount on the -2.5 line.

Me and my bro ski exclusively park unless we want to take a break and run a couple easy runs to cool down. This winter I'll be skiing probs 95 percent park.

okay in that case i wouldn't argue against it then

so yeah in that case i do recommend measuring it out and marking it, unless youre totally positive you can make sure that the tech will know what's up

Since sportchek will be mounting it I'll probably mark it out

3.5 cm back from true center.

Why 3.5 cm back