I put the 064 sized OEM Stihl inner bucking spike on my 462. I think it was Ryan who posted about it a while back, and is where I got the idea. Thx btw.
I knew I didn't want the huge 661R size. I wanted them large enough to get a decent bite on thick bark, and to keep it from hitting the case. I also wanted it to support the bar off the ground while sitting, but not use up 2"+ of cutting length. 1122-664-0505 is the inner one that I used. Retail is around $17. I didn't install an outer, as I really don't need it for what I use the saw for. The outer matching one is 1122-664-0504, if someone wants to run both. I'm not sure if that one fits the small and/or large 462 clutch cover. These two do have the hole for a roller chain catcher too. I also like that the bottom of the lowest spike is rounded, which helps it slide down the log when you're bucking.
Also, some of the cheap aftermarket ones are NOT heat treated, so they can bend if you're not careful. Just need to keep that in mind.