I'm not going to give you the exacts but there are a bunch of things the heads effect. One thing they tend to not effect is the peak volumetric efficiency RPM, although they can.
If the combustion chambers are different you'll need to modify the timing. If the compression is different, timing and VE, and everything might need some warming over but not a lot (hopefully). Then there's the real kicker, flow. If the intake and exhaust ratio is very close and the heads flow more than the old then you'll need to raise the VE in some areas, probably lower it very slight at low to mid kpa but not necessarily!
Best way to go about it, if everything else is equal, is to tune the BLM's in closed loop and look at the VE table vs the previous. It'll give you some good clues.
edit; Read bolt above, not the statement is correct
Last edited by JPrevost; 12-16-2005 at 12:07 PM.
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