[truckin 79]

I lost the original dipstick the my 79 and so replaced it with a junyard dipstick but now it seems like it is to long. I just changed oil 5 quarts and it is way over the full line. I thought sbc dipsticks were all the same but I guess not. Can someone give me the correct length? So when I go back to the junkyard I can get the right one.
Thanks