Is this shock any good?

I've never seen a Sachs with a fill valve on it so I'll bet it's been worked on before. Yeah, it's not a bad oem shock. They come on lots of European bikes. Definitely rebuildable/revalvable.

That's alot of preload!

that's a std monster shock - all the hoop suspension bikes (93 - 01) used the same shock except some of the 900S that had an ohlins. i think seals can be hard to get for them, the place i use to rebuild them usually replaces the complete seal head if it needs a seal.

see what a base penske is worth, i think it'd be a better shock depending on the cost difference between rebuilding and respringing the sachs.

Thanks for the feedback. While I have everything apart, I might as well upgrade the shock if it makes sense.