1st off all my life I've despised almost anything with the 4 letter word that begins with F. GM hasn't made they're GREAT 12 bolt since what the early 70s .I'd LOVE to have a narrowed 12 bolt for the money I'll put into my 9 .It just ain't gonna happen any more . 3+ year's of 8.5s being produced finding one at a reasonable price is next to impossible any more. With the research I've been doing the dirty 4 letter word company used the 9 from 1957-1986 .So they're not only plentiful,They have one hell of an aftermarket. So I decided put pride and prejudices aside and pay less of my HARD EARNED $$$$ into what is most practicle.