Oh man I could talk your ear off about suspension stuff...but I don't have the experience Nick does. (this is not a sarcastic comment, it is a genuine compliment)
HOWEVER.... being the keyboard ninja that I am, until my tiny metal thing with 6 holes punched in it arrives, I am still free to spout off my personal opinion...
You could go really trick with the springs and get some lightweight (like 2 or 300lb/in) springs and use some nice double adjustable shocks, trim the spring so that you are still at stock ride height or slightly lower, but due to the height of the spring, with it being so soft, you will still theoretically have a fair amount of potential energy (I fucking love talking about this stuff) stored up
making your car's weight actually help you hook up at the drag strip, simply by utilizing the potential energy of the suspension.
You would accomplish this by using a softer spring that is much taller than stock spring height...so for example let us say that stock ride height is 10", and the stock front spring rate is 500lb/in, in order to obtain this sweet deal that physics/science has blessed us with, called potential energy, you would need to use a spring of let's say, 200lb/in, but 14" or 16" high. As the new soft spring is so soft, it will compress a bit but you may still need to trim it a little to get the perfect ride height, but the point here is that
because the new spring is compressed significantly while the suspension is at your typical ride height, the springs have stored up potential energy in them, waiting to shoot up (what happens to a spring when you compress it? It wants to expand!...fucking A science is making our cars faster dude!) the front of your car, transferring weight, and helping to hook up the rear!
Now, before you say "Well Mr.Marley, if you have such soft springs, your car is going to bounce around all over the place, and I'm the type of douchebag who always tries to find something wrong with someone says so I can pick an e-fight because I am bored with my life" ....well, BEFORE you say that, this is where your shocks come in to play!
To try and paraphrase Mark Savitske, who seriously has more patience than I think Jesus might, because of the amount of time this man will spend explaining to you all this stuff and make sure you understand his book (or even Dave Morgan's or Jerry Bickel's) because he truly loves these cars..anyway, to paraphrase this enigma-of-suspension, he says
"If your suspension was an orchestra, the shocks would be the conductor." <---see how that is all in red, so you pay attention to it? Might be worth reading this longass post to figure out wtf I am ranting on about... Anyway.. what he is trying to convey (sorry Mr.Savitske if I screw this up a little) is that your shocks are the only thing that are actively applying force to another object. They are not reactive, but uh, pro-active?(I don't think they can cure acne though... and I'm pretty sure that isn't the correct term) but essentially all your suspension, except for the shocks, all have to wait for a force to be applied to it in order to react. The shocks are the only thing that doesn't wait for a force to be applied to it, it applies the force....so wtf does that have to do with my add-riddled debacle of a post? Because properly valved shocks, ideally double adjustable ones, can help to control the rise and compression (compression and rebound) of the springs, and prevent your front end from bouncing all over the place.
So how does this help you, Mr.Granny? Well, you may need to try a few different springs, but I believe Jegs has a return policy for them as long as they aren't cut, so you can essentially try a ton for free...just add labor! heh.. So you will want to find some soft trick springs that are good quality, and taller than stock. I honestly forgot the actual equation to figure the height you need, but its something like the weight of the front end / 2, and then something with how much the spring is compressed stock..it is somewhere in Doorslammers by Dave Morgan. I highly recommend you buy that book, btw. But yea, pick some taller than stock (by a few inches) springs that are fairly softer so that they will compress down a fair amount at ride height, and pick up some goodass (that is the technical term, btw.) shocks...like the ones I use by Chris Alston's company Varishock. They look like this:
Before you buy your shocks, ask to see the shock dyno sheet of them, and call around to a few different reputable suspension shops and ask around. I actually returned my Viking shocks once I did some digging and saw their shock dyno sheet, and it looked like a blind kid playing pin-the-tail-on-the-donkey...just all over the place (no offense meant to the blind, sorry I'm an asshole) whereas the Varishock dyno is straight up in the book How to Make Your Muscle Car Handle (by Mark Savitske) ..but I didn't just blindly take what was wrote as truth, I called around and sure enough I got the same answer over and over-they are super reliable and the sheit (that is a Spanish term for "Totally Awesome). So, I bought them for the front and rear of my car!
As for the rest of your stuff...
You want suspension pieces that won't bind and allow for maximum articulation. Which essentially puts a crapshoot on anything with polyurethane bushings. Not saying that stuff won't work. Just saying poly has high rates of stiction (that one is actually a real word) and does in fact bind. Something like a roto-joint, johnny-joint, or the g-pivot...I think it is called that? The one that Chassisworks makes..that one.. all of those allow for max articulation and won't bind.
If you don't wanna weld a giant tube across your rear frame,
maybe something like the UMI rear shock tower brace
might help..it will at least tie the two sides together... and the HR bar is def wanted. I have a personal theory that although the HR rear swaybar has less rate (a swaybar is essentially a long weird looking spring, and so it has a "rate" just like springs do, this is the force it applies on an object when it is acted upon
remember how I said the suspension is re-active except for the shocks?) than the UMI bar, the HR bar may seem to work better because it mounts further into the frame, and although this fundamentally gives it less rate, I imagine the performance gain from mounting the sway bar "arms" further forward on the chassis must have something to do with the leverage points required by these cars..because the UMI is technically a stronger bar, but it uses shorter "arms" than the HR bar... anyway, that is just a personal theory..not saying it makes sense or anything.
And oh, don't go with coilovers. Whatever you do. They suck for drag racing
for the front suspension on stock mounting location G-bodies specifically. This ties in with the whole spring potential energy deal...but basically since coilovers use smaller springs that are typically stiffer to give added handling performance, they don't have as much, or any, potential energy in them when you launch...now you can adjust the coilovers to add preload, but before some jerk replies with that comment, how many people on here are going to really be able to maximize coilover spring preload and get that right, vs. just twisting a knob on a double adjustable shock?
So yea, did I bore you yet? Can you tell that I just drank an entire Rockstar in like 5 minutes just a little bit ago?
And yes, I can back up everything that I have just claimed with multiple references from text.
Science and physics make cars go fast. I wish I paid more attention in school now that I know it can help me make my car better than yours.
Side note- I have a feeling that if anyone actually reads this, I am going to get a LOT of shit for it...
and oh, if you want to learn about Bump Steer on these cars, I did a kinda not-so-crappy write up with diagrams and whatnot in my build thread. Here is the link to the post:
http://www.turbobuick.com/threads/m...2-street-car-build.362094/page-6#post-3749305