CreatBot DX3 Mod

I am attempting to switch out an old PEEK designed hotend with a Prometheus V2. My issue is the new heat block provides a 3mm hole for a cartridge thermistor but the CreatBot’s thermistor has a 4mm cartridge. I am considering machining a new heat block with a bigger hole to fit the thermistor but was also wondering if I could just order an e3d cartridge since it would fit in the block. Does anyone know if this would work or if I am just better off machining a new block?