Tyler, Better check that block again .Chevrolet never made a 4 bolt 283,so if it is someone has gone to a lot of expense on an old block. Refer to tooltimes post under the thread How can i tell what size my chevy is to help you identify what you have. or post the numbers of the block here and we can help you.It is now 3:05 a m New Years Day. What am I doing here? I'm going back to bed. Later!