ROW vs US 911 SC cams

[IPA]

I'm in process of an engine rebuild.
I'm upgrading my 81 SC to ROW piston/cylinder specs (9.8:1 vs 9.3:1 compression).
I note ROW engine cams have different profiles than US cams.
Any one have knowledge of how to achieve the ROW performance?
Is it necessary to use the ROW profile cams or are my US cams adequate?
Is there a significant difference between the two?

Thanks for any insight.

[Steve@Rennsport]

Same cams used in both engines, but timed differently.

ROW cars had different cam & ignition timing, as well as CR which were all configured for 98 RON fuel which is 93 R+M/2 USA gasoline.

Make sure you have good enough fuel for what you wish to do.

[Determined]

Forgive me for jumping in, I have a 79 SC 3.0 with stock cams. Engine type 930/06, I’ve installed cams properly and adjusted cylinder 1 and 4 valves to 0.1mm. I have confirmed Z1 using the Stomski digit gauge. For this engine and cam is my valve overlap between 0.9 mm to 1.1mm, ideal setting at 1.0 mm? Thank you for your time and support, I only found one reference for a 930/06 (California car) engine but it was not clear to me.

[Bill Verburg]

As Steve says they all use the same cams but there were 3 different specs depending on the year and model, retarded tends to move torque hump to the right, advanced to the left

[Determined]

Bill,

Thank you very much, I am at ease now, I appreciate your time and support.