I purchased a full front and rear disc brake kit from you for my 1974 bronco, will these knuckles work with that kit? And also is the opening large enough to allow me to remove your heavy duty front chromoly shafts with gold joints without removing the knuckle?

You can use these knuckles with the disc brake kit. However, you will need to grind clearance for the calipers to float/adjust, and the holes for the tie rod ends are larger than stock. The axles normally fit through the spindle hole, but it depends on both the cast of the knuckles, and the axles. Should fit, but do not always.