I downloaded the newest LG Mach update cab from here:
http://csmgtesta.lgmobile.com/swdata/WDLSW/LGLS860/ASPRTN/LS860ZV8_02/LS860ZV8_02.S8_02.P25010.cab
And ripped out the V8 tot file:
http://ubuntuone.com/5pFnvuKu6XcYRGx3GBUFdw
I have flashed the above tot file using this: http://androidforums.com/mach-all-things-root/745289-unbrick-unroot-lg-mach.html
I am now running LS860ZV8. It roots fine using motochopper and CWM works also: http://androidforums.com/mach-all-things-root/761013-req-recovery-bootloader-unlock.html#post6155856
http://csmgtesta.lgmobile.com/swdata/WDLSW/LGLS860/ASPRTN/LS860ZV8_02/LS860ZV8_02.S8_02.P25010.cab
And ripped out the V8 tot file:
http://ubuntuone.com/5pFnvuKu6XcYRGx3GBUFdw
I have flashed the above tot file using this: http://androidforums.com/mach-all-things-root/745289-unbrick-unroot-lg-mach.html
I am now running LS860ZV8. It roots fine using motochopper and CWM works also: http://androidforums.com/mach-all-things-root/761013-req-recovery-bootloader-unlock.html#post6155856