Ok so how about just changing out the back components, If i just leave the front derailleur a 3X sram,
can i just change out my back components and shifter,

Like this?


Shimano SLX M7000 11 Speed Rear Derailleur $52.49
Shimano SLX M7000 11 Speed 11-42t Cassette $52.99
Shimano SLX M7000 11 Speed Rear Shifter $29.99
$135.43


And then I need to know if this cassette will fit on my back tire/hub without buying a new one. Is this possible?

Thank you.