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#1 |
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As an old racer thinking about getting my 69 chevelle back on the track - is the 401 alum cyl head acceptable on "all" 375 HP engines?
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Fred Dempsey G/S, H/S, I/S, D/SA |
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#2 |
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It's legal for the 69 396-375. Of course, you should check the guides for the factored HP, the weight, and the specs. All of it is online now at the NHRA site.
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Alan Roehrich 212A G/S |
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#3 |
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Thanks Alan, I have checked all the NHRA specs, factored Hp and such, but was a little confused regarding the 401 alum head use on my Chevelle. At one point in the specs, it mentions the alum head for the Nova and Camaro only, but I have since learned it is also legal on my can. Thanks again for your help.
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Fred Dempsey G/S, H/S, I/S, D/SA |
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#4 |
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Question? Isn't the 401 replacement head an open chamber head at 118 + - CC's? The 396/375 combo is a closed chamber 106 or so CC head. Can someone explain whether one is allowed to modify the chamber or to decrease the CC's on the head to run stock or even SS? Can you run it as an open chamber and are you then allowed to use the open chamber piston that fits the combustion chamber better. Confused on how this works. I thought I saw an SS camaro racer running an alum head 427, but claim the 445hp instead of the 476hp for the L88 open chamber headed motor.
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#5 |
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Mannymen - According to the NHRA specs, the stock cast iron head is listed as 104+cc, and the 401 alum head is at 103+cc. Also, the alum head motor is factored at 405HP and the cast iron head motor is at 390.
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Fred Dempsey G/S, H/S, I/S, D/SA |
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#6 |
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The LS-6 454 SS engine combination has used the open chamber heads at the closed chamber CC for years and years. I machined a number of sets so I know how they got from 119 cc's down to the legal CC number.....
I just had a friend ask me about doing an engine using the 401 heads and wondered the same thing...How did these heads become acceptable for an engine that used CC heads. I am assuming the arguement that the legal iron CC heads are getting harder to find and more expensive is how these aluminum heads came into the picture...... '840's and '291's There are also aluminum CC stock GM versions..... A friend has a set....
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Rich Biebel S/C 1479 Stock 147R Last edited by Rich Biebel; 07-23-2009 at 07:35 PM. |
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