Vss can be made freehand.
Make a tooth wheel. Bicycle sprockets work. My ms let's me program for tooth count, etc.
**** any hall effect will work.
Why spend the scratch on sensors? Pay the $2 to get in the junkyard, buy $30 worth of 3g alternator swap parts, and toss the sensor strings out of pontiac GTPs in your toolbox.
I'm not an advocate of theft. I'm just smoke the ganja and get forgetful. Sue me.
But junkyard sensors are better than advance ZoNAPA sensors, period.
Oem is your best sensor, with the only, maybe, but probs not, exception of only stoopid expensive aftermarket, or diy ones. Yes, you may have to snag three or four. You can say pay or get other shit and cry stoner. Up to you.
Hard but not impossible means is to call Texas instruments. If you get a rare one that you can't source, or want to diy one for MS, or obsolete oem, just call them, ask to speak to an application engineer, and tell them what you need.
Then homebrew.
This is how I fix oilfield tools. If it applies to neutron reactors, it applies here.
Hard. But not impossible.
It was a natural crossover to me. Oilfield sensors on our equipment is usually repurposed automotive.