Changing radiator need advice

I am changing my one pipe steam radiator. the new radiator has taller legs and the connection is too short and has no more slack. do they sell taller on/off valves? or is better to add a nipple to extend it. pls help

I'VE DONE THIS

Unfortunately the rad mfg changed the inlet connection height and created a nightmare for some folks. I've come across this more than once and I've used a sawzall to cut down the height of the legs of the rads. After the cut, use a file to remove the sharp edges. If necessary, a steel washer can take out the rock of the rad due to unequal cuts.

what are odds the legs are hollow? if i cut hollow legs, radiator becomes garbage.

ok after i drill and notice its hollow how can i seal that hole