I have an engine and it is stamped (i stamped it) RDA RS**** I have the letter from ford saying engine number RS**** is such and such age but im worried now that the RDA bit at the front of the number is going to cause a problem at iva as they may take the number to be the full RDA RS****. should i file off the RDA and leave the other bit, not sure what other people have done?

Thanks