The problem is this;
RTV Silicon is not gasolene resistant and will eventually brek down with repeated exposure to it.
RTV on water ports and on both ends but not to seal intake runners. I use a mixture. If gasket is not printed I use Edlebrock Gaska-Cinnch between gasket and head and if printed nothing else on the ports. If not printed I use Permatex Avaition Sealer which does not dry hard and is not suseptile to gasolene.
Possibly those dams of RTV will catch enough gas to make an intake begin to leak.
Hope you accept this as help and not a criticism.
Ed