I have had quite a few RB engines over the years, tried many different pipes also, the best performance that I have had with all the Rb engines is with the 2045 pipe, and depending on the track size you are racing on, the 192 header for the larger tracks and the 198 header for the smaller tracks. The 198 header will give you more bottom end, were as it tops out to quickly for big tracks, the 192 seems more linear, with softer bottom end and better top end.