Its kiNda funny... The 590 has 106 lobe seperation ---"tighter" Lsa's make more cyl pressure all else being equal----that 8.5cr motor On paper is a terrible match up... But it Worked !
25 yrs ago or so when i built my first car ( chebby) i put a 292/108 Isky hyd cam in a 8.2 cr 350. It ran like a bat outta hell when it Shouldnt have...no stall no gear. That 400 combo reminded me Of when i was a kid!