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I currently have a rebuilt 410 +.030 over. It is running '68 68cc heads. my compresion ratio is high enough to reguire 91 octane to keep pinging to a minimum with the timing backed off a bit.
I had to pull the heads due to water in oil (suspect craket head at this point).
I was wondering who has run Edelbrock heads part # 60069 and #60079. one is listed at 72cc and the later at 76cc. How do they run and should I just go with the 76cc to try and get it down to a managable level of compresion for pump gas.
There are several people on this forum running the Ebock heads in general and they seem to be above reproach. Gtex and Ratmoker are two that pop to mind. Maybe they will give you their impressions. I have the Ebock 427 heads but will not be able to give performance input for a few more months.
You will need to do the math on your engine to determine which head will suit your needs the best. Determine as accurately as possible what your current compression is, then make your choice depending on which one will get you closest to your desired ratio. On a typical 410, a change from 68cc to 72cc would drop your compression ratio about 0.4, where a 76cc head would drop you about 0.8.
In other words, if you have 10.5 now, a 72cc head would drop you to 10.1, and a 76cc would drop you to 9.7. These are rough figures, but they give the idea.
never cc'd but i baught the 6006 heads and loved em my truck ran great and made awesome power keep in mind to run the headsyou wiill need adjustable rockers and have to buy different head bolts stockers wont work use arp or whoever you can find em from
Originally posted by FE427TP and dont forget that most of the people I've heard about who CC'd their edelbrock heads found the 72's to be 76
So does that mean the 76cc heads will actually measure 80cc? Just wondering.
Even if my CR goes down to 9.0:1 I will be happy. todays gas just doesn't seem to be worth a damn.
well i'm not sure about that, but I do remember edelbrock used to say they weren't happy with the machined chamber on the smaller bore so they used the smaller design for the 390 bore and kept the machined one for 427's
My Edel 6007's CC'd out at 76, so maybe I was just lucky?!? Anyway, the only way you will get down to a 9:1 is to dish the pistons significantly. Long sad story, but I wound up with some custom Ross pistons to accomplish that in my .040 over 410.
Steve