1997 250 heavy duty

i have 1997 FORD F250 Heavy duty with the 460 and today at work i was underneath it looking at the brakes and doing a trans flush. i saw that in the rear nearthe splitter i have compression fittings on both side of the axle. its a heavy truck with a three inch body lift and 36 inch tires. i know they are illegal but should i replace them immedietly are they dangoures to have on that large of a vehicle. thanks