i have my own carb jetting questions.....

im running a 750 dbl pumper on my 460 with dove-c heads....(used motor - new for me)
early in season after 2 trips out noticed high heat paint flaking off heads.....checked new set of plugs
still looked white as brand new....so i figured it was leaning out big time
original jets in the carb were 80 in front bowl and 71 in the rear
increased jet sizes x4 so 84 in front and 75 in rear....really seemed to make a differance out of the hole..now plugs are just starting to get a light tan color just berely....where do i go from here?
i got a loaner 850 dbl pumper from a friend that im working on rebuliding...but i think the 750 is enough just needs tuning......should the jet sizes be closer together betwen ft and rr bowls?
or should i go up x4 more and see?
one more week left untill i leave for big river..i wanna dial it in ...please help!