looking for lost 340 engine

hi: New at this but here goes.
looking for my numbers matching engine block to my 69 gts. vin #LS27P9B440932.
have owned car since late 1991(dec.) IIRC. It's last tag was 1978 Illinois. Car had over 100,000 on odometer. engine was removed and never reunited for what reason I don't know.
The man that sold me the car owned it for appox. 10 years and couldn't even recall where he purchased it. At the time I was just happy to be able to buy it. I know it's like looking for a winning loto ticket but what the hell. Hoping someone out there can help make another MOPAR complete again.

Thanks any help much appreciated.