My very long experience with garage builders contacting my shop for help has teached me quite a bit about the mistakes that many of them are making when tinkering with their bikes.
A frequent one is ordering and/or assembling new fork tubes. And I am not talking in this post about ordering the incorrect tube length (another costly mistake), but 1- ordering bare tubes and then getting confused when hunting somewhere else for the correct internal parts 2- assembling the forks with the mismatched internal parts (from springs to clips and seals), or assembling the correct ones but in such a way that at the first spin around the block your bike front end is going to leak all its fluid suspension.
So, I have only one simple recommendation. If you are not a pro, don’t do it yourself. Make your life easy. Just buy your (correct length) tubes already completely assembled with the correct internals and ready to go. Several vendors do sell them this way. Including Pro-One selling hard chrome forks in lengths from 2” under to 12” over stock. By the way, a last tip: to avoid leaks, ask them at the same time the volume of fork fluid you should add to an extended front end. Pro-One Performance Manufacturing