The object is NOT to just add mass at the front end of the cartridge. The object was to add mass carefully at the ends of the bar in able to provide a high polar moment of inertia to the cartridge body (to resist the twisting input from the 45 degree - 45 degree input from the record grooves into the stylus assembly). It is
mass management not just the addition of raw mass. The brass U-channel is lead filled at the end. Use the same length of solder on each end although you don't need to measure down to the nearest atom. Burnish the assembly with fine sandpaper for a shiny bright finish, knotch the bar for a press fit from the Grado body, and glue it in place. Then pack the remaining inside of the bar with plasti-clay for further anti-resonant control. The result is significantly better bass performance, dynamic range, stereo imaging, and trackability. All for free.
It even works better than the $1000 interconnect cable from the turntable to the preamp.

If you can't come up with the 1000 centistroke liquid silicon we use for damping the stylus pivot, coils, and tone arm bearings, just send me a tiny absolutely leakproof bottle and $5.00 for my handling and return shipping costs and I will supply the "snake oil" for you.
Best regards,
Frank Van Alstine