Who let that darn Chevy guy in here anyway?
I'll put in my last two cents and then I'll go away.
1. I didn't say to go to larger valves. I know SB stuff is limited, I just pointed out that for 425 ci a 2.05/1.6 combo is small. Reality - deal with it... To work a combo like that, more lift than .544 is required to make bigger numbers. Ford, Chevy, whatever. I think .620 would work really well if you can fit the springs for it.
2. Lobe centers/duration: for engines (Ford or Chevy), more overlap is used for higher RPM and requires more static compression to maintain dynamic compression. 10.5:1 is low compression and you need to keep overlap reasonable. Do not try to run 7000 RPM with 10.5:1CR. This is better suited to 6000 RPM. I still recommend a 114 LC and somewhere around or less than 235 duration. This will keep dynamic compression high. Intake/Exhaust biasing on lift/duration is head dependent and I've already stipulated to not knowing Ford heads and made no biasing recommendations due to my lack of knowledge. Levy would likely be able to guide you in this area. He has test data.
3. It is known that Fords do not flow like a BBC (what does?) so, as I stated before, the Vic Jr may well be required in your large ci application due to limitations in the design that are exascerbated with dual plane manifolds. Additionally, low RPM torque can be a killer in these cars due to excessive wheel spin. It may be advantageous to lose some very low RPM torque in the interest of more power at higher RPM and if the flow is limited by design, the Vic Jr may be required due to the increase in ci. I passed on putting a 540 in my Cobra in favor of the 427 for this very reason and it is built to run high RPM. By the time I am over 500 rwhp (~6000 RPM), I can be hooked up and better able to utilize it.
Like I said in the last reply, Do the cam.
Now I will vanish into the ether...
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