>>4030923>>4030932what developer? if you're using rodinal you should just use stand development (1+100 rodinal left for an hour) and you will get the best possible results
otherwise just follow the dev chart, a three stop push is possible but your negatives will be extremely grainy and contrasty
24 minutes for 3 stops is normal
https://www.digitaltruth.com/devchart.phppic rel is some hp5 pushed 3 stops in rodinal