Need Help Identifying my chevy motor.....

[1984C10StepSide]

Hey everyone, so I have done a little bit of research and found that I can find out what size my motor is and what year range it was made from the numbers behind the alternator. I have them but can not find any information on them really. They are V1042SDN 2EN210127. Any help would be greatly appreciated. I was told that it is a 350 ut the only thing that I found was that SDN could be a 1984 305 from a FBG? Please HELP!!! Can anyone help?

 

[motormonkey]

Many people rely on codes to decipher a engine but there are other ways. The 305 and 350 have many similarities but there are a few differences which you can tell. What is the diameter and width of the harmonic balancer? if it is 6" and about 2 1/2" wide it is likely a 305. Most 350s used a narrower 6" balancer that is only about 1 1/2" wide. Another way to tell is the timing pointer location. Most 350s, except those in vans, have a timing mark on the balancer that corresponds to a tab which is on the lower left side of the front cover. A 305 usually has a timing mark that corresponds to a tab which is in the middle of the timing cover and can be viewed from looking down between the water pump and the front cover. Again if your engine came from a van of cab forward truck(1 1/2 ton and up) the timing marks may be like a 305. I hope this helps.