Perhaps not a common change, and perhaps not an "upgrade" in all respects... I'd like to do some Bowden extruder experiments with my FT-5, but would like to do so with the stock hotend if possible.
This is partially to enable some more scientific A/B comparison ability, and partially because I know my current hotend is all wired up and works well. Also to defer the costs of a hotend upgrade (E3D V6, etc) until after I've proven that Bowden is the way I'd like to go.
With the way the factory FT-5 factory ("Mk9"?) hotend is set up, the heatbreak/throat is simply attached to the aluminum block, which is sandwiched between the heatsink and the extruder body.
I've been unable to find anyone who has done this, but would converting this hotend to a Bowden variant be as simple as removing the assembly from the stepper, bolting the heatsink to the block with shorter screws, and mounting something (with adequate temperature tolerance) to hold the Bowden fitting directly above the opening in the block?