Rlguns

I have had these engines and parts sitting on a shelf in my shop for 15 years. I'm 70 now and my wife want them gone before I am. I am cleaning house and it is all going to be sold or scraped. I will list much of it here so that it gets used.

I was given 5 RD engines and a load of parts. Can the year of the engine be identified by the case numbers? The engine case numbers are; 351-311296, 352-311210, 351-210743, 351-115015, and352-307652. Thanks for any help you can give.