does anyone know the original rocker ratio of a 390? im getting ready to make my cam selection and i want to go with roller rockers and the only ones i can find are 1 to .76 rockers. i dont want to give the wrong ratio and start hitting pistons. so can anyone help?

 

If I remember right, original ratio with non adjustable valve train (hyd lifters) was 1.73:1.

With adjustable rocker arms (solid lift engines) 1.76:1

 

oh ok so if i go after market its just incrasing strength and adding the abilities of a roller rocker. is there a way to tell a difference between the stock adjustable and solid set up?