57chevyman , checked an 82 olds brom has left hand alt brkt. not sure what the engine is. this brkt is kinda big takes three botls to head for upper and lower uses exaust bolt. also 73 3/4 chev pick-up 307 has left hand brkt. one on pick-up is the smallest of the two. two pieces held on by two bolts in top of head has a # 3951337. now I'm not a chevy person so don't know if long or short pumps. why do I have , free! suppose I could send pics if you'd like to see them. let me know.