Upgrading a Seiko's watch movement

Are you speaking of an Apple watch quartz movement? (S9 series) Or are you perhaps referring to a Grand Seiko 9s65 mechanical movement? They are very different things. If you are talking about the quartz movement I know nothing about it.

If you are talking about a Grand Seiko 9s65 movement, it is a superb movement, one of the best you can get in my opinion. But I am reasonably sure that it is not something that you can just purchase, and it almost certainly wont fit in your watch.

My bad, I was referring to the 9S (not S9 :sweat_smile:). I was planning to buy a cheap 9S watch for 2.5k price range and take the caliber out to put in an older Seiko watch which has a 4R35 movement as I would like to give it an upgrade. My old watch has sentimental value but I would just rly love to have an upgraded caliber.

You saying this is not possible? what other options do I have? Would I need to switch the full watch case or can I maybe keep the dial or something?

Hey mrk. I think a GS with that movement starts at about 4.5k, you may or may not be able to find a used one worth having for 2.5k. I think if you are going to do this it would be easier to just switch dials if you can find a GS with the same dial diameter. Not sure if you quite realize it or not but this would be a massive upgrade, 4r and 9s movements are on complete opposite ends of the spectrum of movements. If you can find a GS with the same size dial then switching dials may be more doable.

A better option in my opinion would be to go for a Seiko 6r movement instead. It is still a huge upgrade from a 4r movement, and both movements come in very similar Seiko watches. I also believe that they are nearly identical in size, so a simple movement swap may very well be easily doable. A 9s is just enough of a different size to complicate things.

Grand Seiko and Seiko are pretty independent from each other which would also complicate things, sticking to just Seiko only would likely be much easier to do. Also switching to a 6r would cost a few hundred dollars, while switching to a 9s would cost thousands. Best of luck to you if you go for this.