[android 211]

It isn't until you replace the subframe bushings that you will realize how much the body was flexing. If the front springs have been replaced with something stiffer and you like the ride height then replace the front bar with a TA 1 1/4" piece. GM used 1 1/8" after 1974 except on WS6 cars which got the thicker one. The rear bar was only 3/4". I'd source TA replacement springs all around. 70-74 was lower and stiffer. '75 up was softer due to owner compliants about stiff ride. I thought my '72 was real stiff until I was going over 70 then it seemed appropriate.

[CROCIE JR]

After many years making these cars pull .95-.98 G on sticky street tires and over a G with race tires, none of them had sub frame connectors. You are not going to be anywhere near those numbers with your set up. I have built cars with roll bars (4 point) in conjunction with sub frame connectors and made for a horrible (subjective terminology) street car. So if any of you guys have actual data lets hear it.

[STEELCITYFIREBIRD]

Your tires are a HUGE factor in handling,( obviously your only connection to the road.) Wider, stickier, premium casing construction and profile... and appropriate air pressures.

Controlling forces on them of fore, aft, lateral weight transfer, and their attack angle to the road is how you make them work harder FOR you.

Center of gravity height, front vs rear roll resistance and weight transfer amount and timing is how you make the have more traction and use all 4 tires.
Overloading a tire makes it lose traction....fast.

A stiff chassis is less forgiving ( has a smaller sweet spot when balancing handling)....but responds to smaller swings at adjustments.

So, for a street driven car where you still want ride quality, you compromise.

Aluminum heads and intake, moving battery to lowest area in trunk will both lower center of gravity height...and add needed rear weight. Good stuff.

The front end alignment and geometry are VERY important details. Factory alignments and geometry are designed to give you a bad feel, understeer/push the nose... so average driver doesn't overdrive the car, past the limits of traction of the tires.

An appropriate centerlink and ride heights will make for no toe in when turning and minimal bump steer.
Aftermarket Spindles with optimized geometry.
Appropriately valved shocks to control weight transfer timing.
The hard and "more" expensive stuff.

The cheap stuff:
Lower center of gravity height, raise front roll center.
Building anti dive into the upper a arm mounts, taller upper ball joints to increase camber gain, raise front roll center. Twist in spring spacers to stiffen front springs, but not installed so as to not raise ride height..... without any disassembly. Use proven competition alignment settings.

I've seen some stock cars use some pretty well thought out methods to greatly improve handling and still use mostly stock components...just relocate mounting points and some taller ball joints in the right places.

HTH