hell.... B and D series motors,on all my cars i have a muffler guy that 1 off's all my exhaust,my GSR build is using a 2 1/2 in piping,catco hi flo cat,no res. and a magnaflo muffler! hell i had about the same setup on a mini-me setup i had in my EF! so go with a 1 off setup! you can get all the right bends,and get the right amount of backpressure ya need also! cant jus free it all up...lol... like someoe else said "no exhaust"...lol...