The easiest ingredient to have quicker quarter mile times is to shake those unsightly pounds. So let's put your GS on a performance diet. The following illustrates the various weights of factory and some aftermarket equipment. Always keep in mind, for every 100 pounds taken off, you gain about a tenth and 1 mph. That's free HP! All weights in pounds.
Fact. 1970 GS Hood 85 Glass Hinged GS hood 35 Frt Bumper 27 Glass Front Bumper 3 Rear Bumper 34 Glass rear bumper 3 Fact. frt buckets(2) 90 Plastic high back buckets 23 Bumper Brackets (4) 24 Trimmed bumper brackets 12 Rear Seat, top/btm 40 Remove rear seat 00 Front Disc Brakes 60 Frt Al. man.drum 47 Brake Booster 10 Remove brake booster 00 Inside door braces (2) 26 Remove inside braces 00 Power Steering 30 Manual Steering 00 Buick Mags&tires 90 Weld Wheels/frt drag tires 24 Buick Mags&rr tires 94 Weld Wheels/MT tires 44 Spare tire 45 Remove Spare 00 Deadening material 35 Remove material 00 Total Weight 690 Total weight 192 By doing the above (which I have done) would take approximately 498 pounds off your Buick. This will increase your 1/4 mile times up to 5 tenths and five mph! Of course your weight may vary depending on the type of scale you use. Now, if you really look hard enough there are many more places to shave the pounds. One thing to keep in mind, is that the more weight you take off the less streetable and original your Buick becomes. You should store away any original equipment in case you get the urge to restore your Buick down the road. So be smart about it. It only takes a few ounces that add to a pound and 1600 ounces to 100 pounds. My '70 GS weighs 3000 on the nose though I did have it back halfed with 14 x 32 tires, which also cut another 200 pounds off the car. As for the drum brakes, I am doing 135 in the 1/4 and I'm running aluminum manual drum brakes all around.