Here is an interesting and rare option on this car. These are mounted up inside the cowl on both sides. One looks like it’s been replaced at one point. Both of them work...but are nasty.
The forced air I-55* forced air option with the switch in the radio bezel. I had that on one 70 stage 1. * --I2 Forced Comfort-flo Ventilation option. I look it up and saw that only 333 70 GS Buicks were ordered with this option.
My GSX had them, rudely installed and heavy IIRC! What a terrific project car. Don't know what the initial investment is, but this looks to be one that has a chance of not going underwater.