My front 3 cylinders on my 261 run though an ordinary stock manifold (including heat riser) which is cut off between the 2-3 and 4-5 exhaust ports. The rear manifold came from a cabover truck and this manifold exhausts just ahead of the bell housing, exhausting cylinders 4, 5, and 6. I am running a straight pipe from the front manifold in the stock location down the left framerail. The rear manifold makes a bend just behind the transmission and another bend to run down the right framerail. I temporarily ran straight pipes which stopped just behind the cab and that was WAY too loud. I had a couple flowmasters sitting around so I stuck them on the ends of the straight pipes and made some 'tips' that direct the exhaust down just ahead of the rear axle. This really quieted things down--almost too much. You can just start to hear it cackle a little about 2700 rpm, and I normally don't push it that hard. When the flowmasters die I think I'll go with glasspacks and get the pipes clear out to the rear. I wanted to wait on mounting exhaust pipes until I figure out a way to mount a spare under the bed, which means figuring out which wheel bolt pattern I decide to use (5X5 or 5X4.75)
