Thread: Head questions

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Originally Posted by Pnaples92

I’m currently building a 454 for my project and I have a set of 6258723 heads and I was wanting to if these heads are worth keeping. I’m looking to build about a 500-600hp engine. I need it to be able to rev to around 7000. I was just wanting to know if these heads are up to the task of what I’m looking to do or should I be in the market for a set of rectangular port heads.

There isn't a whole lot of information out there on these heads, but what I have found makes me think that if I were looking to make a 454 run hard, then this is one of the part numbers that I would consider. They are open chamber with valves of 2.19"/1.88", which is, I believe, as large as Chevy fitted their cast iron heads with on the assembly line. The storied LS6 motor (factory 425 hp) used the same size valves, so there would be nothing to be gained by trying to fit larger valves. I have not been able to find flow numbers on the heads, but again, if I were beginning a BBC naturally-aspirated build and had these heads, I would not be looking for other heads. One thing that I would definitely do is to cut the valve seats and install hard seats for unleaded gas, if it was unleaded gas that I would be using.

Now, I believe that answers your question, but I have a lot more to say to you if you will bless us with your intentions (vehicle type, weight, intended purpose, fuel to be used, transmission, rear gears and tire sizes and so on and so forth). If we knew more about what you intended to do with 600 horsepower, we may be able to save you some money and some grief. For instance, twisting a BBC to 7000 and having it live will take a few buckets of money for valvetrain pieces.....money that may be applied in another way if you were to choose a different route. If I were able to offer you a way to make 700 horsepower for half what you would spend on the BBC, would you be interested?
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