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Need help with DCR calculation

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Old Jun 2, 2009 | 09:10 PM
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Default Need help with DCR calculation

I'm in the process of choosing/installing a new cam in my 69 L 36 with M-20, 2.5 dual super turbos and currently 3.08 rear diff. Can someone out there calculate my dynamic compression ratio and compare it to the cam I'm thinking of installing? The cam I'm looking at is a Comp Cam XR276HR, 224/230 dur @ .050, .510 valve lift, 110 LCA ,106 ICL and with valve timing measured @ .006 lift the intake closes @ 64 ABDC. I am under the impression DCR needs to be about 7.5 to run on 93 octane ? Is that true ?

My motor specs are as follows

69 427 390 hp
Silvolite cast 9.5-1 pistons .030 over with 13cc dome .020 below the deck
Felpro head gasket 4.540 bore .041 thick
3964290 heads at 104cc
3.760 stroke
6.135 rod length

Any help would be greatly appreciated. THANKS.
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