OK, The Hemi VVT's work backwards from full advance.
Full advance is the default/idle position and they retard from there.
So the stock phaser can retard 14 cam degrees (28 crank degrees) and if you fit a 7deg limiter, it then limits retard to 7 cam degrees(14 crank degrees).
Now with the stock cam we know the start position of the cam as the cam is ground with 14 degs advance and has a LSA (6.4L) of 120.5.
So at full advance it has an ICL of 106.5 and exhaust 134.5
Now with an aftermarket cam the LSA and cam advance are most likely now different.
I cant remember the 270 off the top of my head but do know the 274 which is probably similiar.
It has LSA of 116 and is ground with +3 Adv.
So installed and at full advance this cam will have an ICL of 113....but the PCM will still use the numbers 134.5 ex and 106.5 int as it doesnt know the cam has changed.
This cam will like to be run somewhere from 113ish to 119ish ICL so we will have to tell the PCM to keep it nearly fully advanced and retard up to max of maybe 6 degs.
So the exhaust cam table numbers( as these are the numbers that actually control the cam not the intake numbers) will run from 134 (full adv) to 128 (6 degs retard) approx.
This would make the intake go from 113 CL to 119 CL Actual.
The exhaust numbers would be 119 to 113 CL Actual.
So you can see that when swapping cams the numbers can get a little complicated.
Hope I have explained it clearly...if not, ask away..
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