What carb are you running??
4.10 gears should pick you up 3 or more tenths.
What is your 1/8 mile MPH
two things jump out 60' is poor gear and maybe a TQ will help that a lot. but your 1/4 mph is low for 13.3?? I would think 104 or so would be more in line.
running out of fuel? But maybe a bad torque curve where you are forced to shift into third??