They actually came out with a vacuum tank (an oxymoron if ever I've heard one) and had a second pump under the fuel pump. The vacuum canister lived under the righthand front mud guard I think, rusted out in the first yr or so and was deleted. The mechanical double pump cost a fortune, so they were replaced with the single fuel only pump ..... the wipers stopped at the base of a hill, but made up for it on the way down the other side, a quick launch off the lights (well, quick for those days) resulted in no wipers, a quick wipe as you sorted where second gear had gone on the "3 on the tree" and then the wipers stopped again while second gear wound out, screaming for mercy in the gearbox the whole time ......
The early Falcon was the same, but you learnt, after the second gearbox, not to double shuffle back to first, the cluster gear exploded if you did it too many times and were a tad quick off the clutch and planting the throttle to the floor to get away from the corner faster, the Holden gearbox just screamed for mercy for ages, before you pulled it out and fixed it ...... great days

T1 Terry