Thread: Holley rebuild
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Old 12-22-2016, 04:07 PM
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Join Date: Dec 2015
Location: N. Richland Hills, TX
Cobra Make, Engine: Backdraft Racing, Roush 427
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Quote:
Originally Posted by jetblue69 View Post
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.
So what would you suggest. I have 3 new valves, 2.5, 6.5, 10.5 that came with the kit. I'm not sure of the cam. It's on a S/B 427 Roush R .
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