My conversion moves the reverse lock out up next to the shifter.
I use the position where the CAGS solenoid goes. Quite often this boss isn't machined so I have to put the gearbox casing in the mill and machine it out and tap it.
Here's a pic of one showing the reverse lockout solenoid below the shifter.
I do the complete the conversion with a billet shifter and a custom alloy gear knob (a few designs available). The box also gets billet steel keys in 3-4 and 5-6 synchronisers and a steel shift fork from the viper box for 3-4 selector. The conversion is $1100 all up.
These mods seem to keep them alive behind big HP motors. This box is in Garretts blown LS1 powered Superformance making 550 RWHP and it's still going strong.
Cheers