What would cause hte front end to pull form side to side under hard braking, as soon as I correct for the sway it seems to switch sides, but once the car is slowing down normally there is no pull, its kinda scary though, only happens under hard braking though..

Check the shim packs and make sure is not loose. Also check the upper control arm bushings. Those are the #1 and #2 causes fro that condition.

It doesn't really sound like a brake problem, it's probably a suspension problem just as Dennis suggested. This sounds weird, but if everything is ok up front, you should also check your rear suspension. My dad's car had the same problem as you describe, and after a lot of troubleshooting and headscratching I found that one rear shock was totally shot. I changed them both, and the problem was gone. Can possibly be a problem with the rear bushings as well.

would bad bushings (worse on one side) on the top of the rear springs do it?

would bad bushings (worse on one side) on the top of the rear springs do it?
If your talking about the rubber insulator pad that goes on the top of the rear springs,the answer is no.
I would check the upper control arm bushings very thoroughly.Also jack the front end up under the lower control arms and check for upper ball joint play by pushing in on the top of the tire and pulling out at the bottom of the tire.
The way the car is handling now may even be related to this
http://www.chevelles.com/forums/showthread.php?t=97981
Did you ever figure out that noise?

would bad bushings (worse on one side) on the top of the rear springs do it?

I wouldn't think so either, but bad rear control arm bushings could possibly cause it, by letting the rear end move out of line or out of angle when you brake. But I think you need to look at the front end first of all.

You might also check the toe. Under hard braking, too much toe-out can cause the car to be twitchy.

Bad bushings may also cause the toe and maybe the caster to go funky when you slam on the brakes.

Does it always happen on every road?

K