we had a timimg light on the truck like two years ago, we got it all hooked up and started low on the degrees and couldnt see a mark anywhere, so we carried our way all the way up to 42 advanced and still couldnt see anything,, it didnt even change the idle... so with this happening like 2 years ago, and the guy from jegs telling me that the hei on a 283 needs to be degree'd, before i told him this story,... there is truth there and i would really like to get this all correct before i drop the engine back in the truck so i can get an accurate reading... before we just went off of the sound, idle and the way it ran.. and thats kinda retarted so i want it right