Does anyone have any experience locking a distributor for a 13B? I need to get instructions on how to cancel out the vacuum advance

 

Why?
If you remove and plug the vacuum lines to the L & T vacuum diaphrams you will disable the advance.

 

Wouldnt the centrifical weights still move inside the distributor?

 

Yes but mechanical advance and vacuum advance are independent of each other. Vacuum advance is only there for added low end/part throttle advance for economy reasons. Vacumm is lower at full throttle so it isn't really doing anything at full power. Just disconnect the vacuum lines. Leave them uncapped on the distributer side though. Only plug the engine side of the vacuum line. There are threads here somewhere that show how to "lock" the distributer.

 

Easiest way to "lock" the dizzy is to remove the springs from the advance weights.