https://www.sourcebmx.com/products/s-m-retro-shafted-on-redneck-stem
ye +1 for using an old BMX quill instead of an adapter. Will suit the build more imo.
You don't need to spend that much though. But you could...
@Maj started
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https://www.sourcebmx.com/products/s-m-retro-shafted-on-redneck-stem