Help Identifying engine

[noguirre71]

Hello everyone, I really enjoy reading and learning as much as possible off this forum but with that being said I am far from an experienced mechanic or automotive tech. So i have a question to ask fellow members, I'm in need of help identifying this engine. I have a couple pictures and if more pictures are needed I can snap a couple more but that would have to be tomorrow. A little info on this engine...My girlfriend has an early '90s silverado that has been sitting in the back yard of her house for about six months and is looking to get rid of it so she called me asking if I was interested in the engine inside the truck for my 71 C10. From what she knows about the truck and the engine is that it is NOT the original engine and had been put in not too long ago. She said it was mine for the taking and I of course wouldn't mind having it but I just wanted some help identifying it while I was at it. Thanks for the help guys I really appreciate it. Hoping one day to be on the other end of posts like these.