Hi, just joined. I have a '08 Tahoe LT, 5.3L, 4WD in need of an exhaust replacement after the cat pipe. I went with the walker ss quietflow setup. I have both the muffler (21614) and the resonator pipe (55565) but having trouble with getting the flex extension pipe (52477). It doesn't seem be in stock with anyone since the beginning of this year. I do see AP has their version of this pipe (38961). Has anyone mixed and matched AP pieces with walker pieces? I'm thinking the pipe diameters between companies may be different where the clamps will not seal properly. Any help/advise is appreciated.