My VIN is 1343711519410 its a 71 can anyone decode this for me and tell me if its a real heavy chevy as ive been told that the 13437 states that it is a heavy chevy?????

71,
There is nothing in the vin number that indicates a Heavy Chevy. If you have the build sheet and it shows the YF3 option code, that is the only way I know of to tell for sure. There are some tell tail signs, for instance the door panels on the Heavy Chevies were different than the rest of the Chevelles. But without the correct build sheet for the car, there is no way to tell for sure. As you can see by my signature, I have a few clues ;)
Hope this helps,

I think this VIN is Canadian. You can talk to GM of Canada and get all the info on it if I'm right. I don't have the contact info for them, but someone here does for sure.