throw in with all that said RR and GTX like super Bees and R/Ts in 69 had to different AG/RC air cleaner bases the 383 RR/SB version had a longer neck the 440 GTX/R/Ts had a shorter neck for a stock set up so then the factory knew they needed two differnt bases due to the B RB blocks I let the hood dowm nice and easy FWIW and then