Specialized Chisel/Epic Coil?

I wouldn't recommend it. Extremely short stroke coil shocks leave a lot to be desired. You have to run such a high spring rate to hit a reasonable sag number and not be bottomed out constantly. The progression of an air shock really lends itself to a shorter travel bike, unless that short travel bike has a VERY progressive leverage rate.

I have looked at it on my Chisel just to see if i can get a bit more out of it, and I feel like the Deluxe on the back is already pulling a lot of weight. I feel like the progressiveness the bike has and likely needs to get away with what it does, it needs an air shock. Even a progressive coil might not be enough. I have yet to blow through all 110mm riding early season, and I've for sure been taking it down trails it was not designed for. I'm pretty dang impressed as it does seem a bit bottomless and pull off all the moves, but I feel like a coil would blow through the stroke pretty quickly. Is there a float X in eye to eye and stoke? That might make it a bit more of a tank. 

For that size you can get float X or super deluxe fairly easily, Vivid airs come in that size also. I'm sure I saw a float x2 in that size once (it looked very chodey) but it does not come up in any listings I can find now so it may have been a different size and already stuck down a bit. I haven't seen anyone put a coil in one yet, I think with that length of travel, a good air could be fiddled to do most things. I've found I don't seem to use much of the travel in the rear on my evo. I'm running it bang on the 25% recommended sag, but it seems very rampy towards the end. I haven't looked at what tokens are in it factory as the bike seems to feel fairly balanced. 

I would maybe just start with a retune, I know the Evo shock tunes are firm by design. I have a chisel too, and its anything but settled on high frequency roots and rocks. To me this is a trade off for really great pedaling performance, less great small bump sensitivity. 

The Fox tunes for these bikes are very digressive to optimize for pedaling performance.  I actually found that the Rockshox Sid 3 position to be more plush in the open mode than the Epic Evo Fox tune shock.  

I haven't fully gelled with my Epic 8 Evo but do enjoy pedaling it.  Right now I'm waiting to see what the Forbidden Reya looks like but something like that seems better for my needs.

This is the details for the float on the evo, I guess the dcm001-b and ssr001 are the actual tune codes? 

2025 PERFORMANCE SERIES FLOAT

Serial number: 1167103-0213-t
Part number: 972-63-268
Description: 2025, FLOAT, P-S, A, 2pos, Evol LV, Specialized, Chisel Comp Evo, 190, 40, 0.2 Spacer, DCM001-B, SSR001, CMF, Standard Logo, N/M, OE

Does anyone know what codes are on the deluxe on the chisel comp?

The frame doesn't have to be REALLY progressive like some Forbidden bikes are, anything 30% and above is fine. I've been running a short coil on a SC Tallboy for quite a few years, and know others that do so as well. It is very good. 

But the Epic EVO/Chisel platform is definitely not progressive enough, and the falling rate at the end of travel deems it very unfriendly to coil shocks. No bueno.