2:1:2, 2:1 2:2, exhaust 222 or 555cams. I want good low end torque without ruining my hwy cruzing. I will be traveling long distance pulling allot of weight my belly and wife and trailer. I do not want to get into the top end or put high compression pistons in it. I like the look of dual exhaust but have been told 2 into 1 is the ticket. too many choices!