Thx, let me know. I also have Fox SC, 34.
How it's possible to install SlackR? AFAIK it's for IS42.

Here is what the 9point8 website says.

" IMPORTANT COMPATIBILITY INFORMATION
Slack-R is now compatible with MOST Tapered IS headsets. There are 3 different styles of upper cups now to go along with the IS52 lowers. IS41, IS42, and IS42S.

IS41/IS52 will fit a number of bikes from manufacturers such as Yeti, Santa Cruz, and Trek (eliminates the need for a Knock Block in most cases). Cube is an exception as they use a deeper upper bearing seat and the Slack-R IS41 will not sit properly in the Cube frames.

IS42/IS52 will fit many bikes from Cannondale, Norco, Marin, Orbea, GT, Revel, Scott and many more including some Specialized with a standard depth IS42/IS52 headset. Standard bearing seat depth is 3mm

IS42S/IS52 will fit Specialized bikes that have the 6.8mm deep upper bearing seat. (some Specialized bearings sit deeper than the standard IS42 geometry so they require their own specific top cup to insure proper fitment)

Headset types do vary across the same manufacturer, make sure you are sure what kind of headset you have. (IS/EC/ZS or hybrids of these)

Some IS bearing seats in the frames have a smaller bearing seat inside diameter than others so in some cases a bit of sanding will be required to fit in the 34.5mm upper sleeve and 44.5mm lower sleeve. In most cases the frame allow the kits to drop right in but in some cases opening up the upper and/or lower bearing seat inside diameter(s) will be required so double check your frame clearance prior to ordering if unsure.

Contact support@9point8.ca if you are unsure about your application prior to ordering."

I have both the FM1002 and the P9. I like them both. The P9 needs a Slack-R kit in the headset to get the full potential of the bike. But fully sllackerized, the P9 is a great bike. FM1002 is a more modern take. And is also a great riding bike. If you used offset bushings on the FM1002 you could probably use your existing shock and not change the geometry. Maybe lose 1/2" of trave. No biggie.

I built my FM1002 with a 170mm Lyric fork. The bike feels quite natural with this fork.

I just spent the better part of a week on my new build in Moab Utah. The bike (and I) survived lots of drops on a couple of trips to the Whole Enchilada trail system.

I have both frames. I think that the 936 have better looks: The downtube is prettier when it is a straight line. 936 has better entries in the frame for cables (screw on lids).
The Fm 909 is just slightly lighter than the 936 std-model.
909 ha better placing of the rear suspension (easier to reach lever).
In some way I like the feeling in 936 better when riding.

Is there any difference between the two regarding rear suspension when riding? Or any other differences in bike performance between the two outside of the cosmetics?

The shock bolt is 8x40mm, and you need bushings or needle bearings to fit 8x30.

I went with the RWC needle bearing kit since the eyelet end is the one that rotates on the FM1002 and 1001. So far it’s been great.

If you want to run bushings I’d suggest pressing out the metal ring that RS puts in their eyelets (for use with their full metal bushings) and running Fox DU polymer bushings.

I went with this. "Fox Racing Shox Shock Bearing Assembly Black, 8mm x 30mm"  It gave me some trouble. Since the inside hole diameter was closer to 9mm. And the FM1002 bolt was 8mm x 40mm.

Thanks. I am also building an FM 1002 with some decent parts off another bike. A few new parts thrown in. The wheels on the FM1002 have Maxis DHF and DHR tires. That bike will be for more aggressive riding. This fm909 bike will be for more flowy and longer distance riding. And maybe some cross-country racing. But it will have to handle occasionally more aggressive downhill riding also. In Western Colorado sometimes the long flowy all day in the saddle trails have some tough ledgy or rooty sections to get through.