Date coded 340.

I have a 69 Formula S 4 spd Mod Top. There is only one other 4 spd Mod on the registry so there can't be many more than that out there. Unfortunately mine is not numbers matching. I have a May 69 date coded 340 now. The scheduled production date of my car was 9-10-68. There is a Jun 68 date coded 340 with assembly date of 9-5-68 and vin number BH29P9B134206 for sale locally for $3800. My VIN is BH23P9B138784. Question is, would having an engine so close to the original help the value of my car anymore than the May 69 block I currently have?