I bought an M25 X-Treme for an SUV I have. Way too much chrome on the front, so I bought two "used" heads from Blinder Guy; to give me a total of 4 heads up front. The heads I bought with the complete M25 kit are the older J15 ones. The two from Blinder Guy are J16. When the installer hooks up the two J16 heads, will the system work okay? I'm assuming so, but just wanted to ask. Does anyone have this set-up already? Any information would be appreciated.