I think 300ft lbs is right on the edge of most half inch drives capacity. Can grab a decent ratchet and torque til it breaks and you will be close
if you have the right 3/4 drive socket and breaker bar you can get something like this for relatively reasonable amount.
https://www.amazon.com/Neiko-20743A-Digital-Adapter-Foot-Pound/dp/B009GLITFW/ref=sr_1_2?dchild=1&keywords=torque+adapter+3%2F4&qid=1632147711&sr=8-2