road cranksets are engineered for the narrower frames use on the road. This will make correctly setting one up on your MTB very difficult, if not impossible.
there are older MTB triples for MTB use... Co-op bike shops keep a wide range of cranksets around....
sorry, but i can't say for sure which setup will fit your bike. Look for an older shimano deore lx or altus triple in the ratios you want, possibly...
another route would be re-ringing your present crank with ratios more suited to your use of the bike... 48-38-26, or something similar.... VUELTA sells a wide selection of rings in many BCD patterns...
your present crank set is a 104 BCD four... changeable rings, right?
Last edited by maddog34; 12-11-17 at 12:58 PM.