I have a question. Roughly how much horsepower would I gain if I add a set of JBA headers and how much work would be involved in installing them. I have a 97 f150 with a 4.2 v6. I also have a flowmaster duel exhaust system and a mac products intake.

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From most of what I have researched you are looking at 5-7hp in the real world, more if you had internal engine mods. Even more if you would go to the trouble of a 2 1/2-inch by 3-inch Y pipe with a single set of high flow cats. Figure about 6 hrs. installation time. I have been debating getting them for my truck but it seems like alot of work for what little is gained.