School me on these spark plugs

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My Edelbrock 60779 RPM heads call for the Champion rc12yc plugs. I have been using the Autolite AR3924 plugs. At the moment my local store is out of the AR3924 and just have the 3924. Any concerns using the cheaper plugs. The conversion chart I saw says this particular Autolite crosses to the Champion listed above.
The regular 3924 is fine. The only difference is the "AR" series has the electrode cut back some.