Thread: Holley rebuild
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Old 12-22-2016, 02:22 PM
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Cobra Make, Engine: ERA #816, 427 Side Oiler
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Quote:
Originally Posted by Axel 427 View Post
I got my self into a pickle. I torn down my Holley 670 with vac.secondary. I didn't pay attention which power valve I took off the front and back. The stamped numbers are different. One valve says either 589 or 586 and the other says 451.
The rebuild build kit came with 3 valves, 6.5, 10.5 and a 2.5. Any advice with be greatly appreciated.


Vance
Well, stock should be a 6.5... But, if you have a somewhat healthy cam that's not going to be the one you want. More cam = lower number power valve. On a naturally aspirated engine of course. Vacuum at idle (full vacuum, not metered) divide by two and if it's a whole number pick the power valve with the next LOWER half number.

Of course the ideal way is with a vacuum gauge and a air/fuel meter but that methodology will get you in a really nice ballpark. I've done it the old school ways for years and it always worked for me but I'm sure some of the internet commandos on here will try to sell you the Brooklyn Bridge.

Last edited by jetblue69; 12-22-2016 at 02:29 PM.. Reason: My spelling sucks!
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