Brake Light Flickers... occasionally.

[jugadro]

Ok, so I have a 1970 K/20 with a BB 402 in it.

On occasions, my brake light will flicker. It used to do it only when I accelerated, but then I set the timing a little and now it flickers with no rhyme or reason.

I first thought it was a parking brake issue, but found that I have no wires connected to the parking brake. So now I'm thinking its a vacuum oriented... maybe? I haven't had any brake troubles, but maybe I should bleed them anyway??

Any suggestions would be great. Thanks.