I finally finished up my 026 project. Actually it is a MS260 that I bought with a bad piston. After a lot of reading on this site, I got it all together and running, but haven't cut with it yet.
I saw a few posts about putting larger spikes/dawgs on an 026, but not any real definite answers. I was able to install some 044/066 spikes on the saw and get them to work.
What I did to the saw...
Installed a NWCS dual port muffler
Widened the exhaust port and 1mm higher and polished
1mm lower on the intake and polished
Sanded and repainted the clutch cover with Stihl paint
Added the 044/066 spikes
Swapped in a wt426 carb
Put in a new piston/rings/wrist pin bearing
Added a Stihl 20" bar and .325 chain
As far as the spikes go, the inner spike was a simple swap. The spike that mounts on the cover side was a different story. I had to drill two holes next to the existing holes on the spike to get the inner and outer spikes to match up. Also I will have to cut a small notch in the back of the cover side spike to allow access to the forward bar nut.
The part numbers stamped on the spikes are 1122/06 inner and 1122/01 for the cover
-Brad