xtetra

I have a 1981 Seca (XJ750RH) which is in need of new exhaust system. I've met Seca owners who replaced the OEM 4 into 2 systems with MAC's 4 into 1 on their Secas and were quite happy. What I didn't think to ask them was whether or not they had to change the size of the carb jets and or adjust/balance the carbs. If anyone has had any experience with this replacement/modification I'd appreciate hearing what you have to say. ie, Did you have to re-jet? Did you like the performance? How did it sound afterwards compared to the 4 into 2 etc? Thanks in advance for any input. John