I'm looking to get 2nd lockup on my 47RE for towing. Anyone achieve 2nd lockup by changing the VB?

 

My VB was modified for lockup in all forward gears.

 

Aftermarket VB or stock one was modded to do that ^? any drawbacks to doing that?

 

After market by Dave Goerend.
Back when he rebuilt my transmission, the all fwd gear lock-up cost a little more than 2nd gear.
Do I use it? Yes. I go 1st locked up when crossing rough ground with my slide in camper