El Camino 1970 LS5 360hp when Impala is 390hp, corvette the same

Well, camshats and cam gears can bump a car up 20 hp, but you said that they are the same, however make sure they are tuned. In addition, camshats need a higher static compression piston. The extra 30hp may come from everything working together more smoothly. Even though you have a lot of the same things in both cars, they might not be as well tuned. Also, check the exhaust system.

The 390hp passenger has the same style exhaust manifolds, however the contradiction is the 390hp Corvette may have (unverified) a less restrictive design. The factory rated the 454 LS5 in the Chevelle/ElCamino at 360hp. So with everthing the same why 360hp as opposed to 390hp. Tuning is not the question. Factory rated HP is. I have factory info that it used its own exhaust design when engine was dynoed to determining HP. Ray...

Check the stroke, also sometimes I have heard that the manufactures did not release the true hp for some kind of insurance reasons...the El Camino was not supposed to be a Hot Rod like the Corvette. Now I know an old Toyota is not the same thing but they got different hp ratings from basically the same engine. The 1.1, 1.2, and 1.6 3K engines have all the same parts but the 1.2 has a slightly longer stroke giving it 13 more hp and there is a 3K-B that has 23 more hp by using heavier valve springs letting it go to 6600 rpm's instead of 6000.