I've been running the same engine, a 270 GMC, in the same pickup since 1978. it has had different intakes, exhaust, transmissions. and rear ends. In an old book my brother had in the '50s, Souping the Stock Engine, the stressed breathing. The old engines were very restricted in both intake and exhaust. The largest and cheapest power gains were made with multiple carbs and duel exhaust. A good cam came next. I have had three different exhaust systems on my pickup and there is one more to come. First was Clifford Viper tube headers, 2 1/2 collectors, duel glass packs, full length pipes with an "H" pipe, one on each side. This produced the highest RPM. Next was Fenton headers into one three inch flowmaster exiting in front of the driver side rear wheel. This sometimes hurt my ears not with noise but some strange pressure thing. It literally sucked but it sounded great. It lost both bottom end power and top end. Last was Fentons and 2" full length straight duels,both exiting at the read bumper on the driver side. Way too loud! Two trips to Reno through Virginia City and I added two 18" Cherry bombs. This is a great sounding set up and pulls well through the full RPM range. It still does not wind as high as the first system. I will put the Vipers back on with these pipes. Exhaust is important to these engines and I think duel exhaust works best. Just my thoughts. Tom
