10.2 to 1 in both my 493" RB & 408" Magnum. Both have aluminum heads, pistons 0 decked with high quench heart shaped chambers. The RB has reverse dome that matches the Indy EZ chambers. The Magnum has flat top pistons with Eddie heads.
Both motors crank 200 psi warm. I run 35* total advance locked in on the RB and reflashed factory JTEK computer controlled on the 408. They both run on California 91 ethanol pump swill. No detonation even on hot days.
(Installed on 105* centerline)
Last edited by jbc426; 02/21/20 12:21 PM.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
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