dual vacuum line wastegate single vacuum line which is better?

[crashedout1]

I have both but I don't understand why Buick did this the dual was used on the 85 and single on the 84 right? But why ? And what are the pro's and con's ?

 

[BRAD_PADGETT]

The reason for a dual line actuator was to help with vacuum issues when going up a hill as I recall. 84 and 85 were both dual lines. They both work fine. All aftermarket ones are single line.

 

[crashedout1]

Thanks for the info I learn something new here all the time