Originally Posted by neo_pop_71

I can't speak to the exact tooth range you're going with on your 6 speed cassette but I was able to run a 6 speed freewheel with the Cyclone GT rear derailleur on an old build for a buddy a couple years back. My Cimarron has Shimano 6 speed "Deerhead" XT derailleurs with a double up front on the crank; I was able to adjust the limit screws enough to run a new 8 speed freewheel with 8 speed Shimano "brifters" and I've had zero issues. I can't imagine you having any snags with a 1x6 set up, especially if you're running a friction shifter but an index shifter should work well too.

+1 I'm also looking forward to seeing the finish!