Bill,
I'm not shure there is an absolutely correct way. I'll give you MY ideas and you can select what works for you.
First, the factory probably did a good job of designing the sway bar links, so I'd try and match any aftermarket links to what Chevrolet origonally put on the car.
Second, if there is a good reason to change from the dimensions of the factory links, do it, otherwise modify the aftermarket links to match the factory stuff.
Why change length? Perhaps using a stock length of link on a lowered car would put the sway bar at too great an angle to the end links. Maybe the dropped center of the swaybar is rotated enough that it could hit the vibration damper on the engine. If the end link is too long, it might hit the upper ball joint nut, or subframe around the spring pocket.
I would not go crazy shortining the link, as it will develop too much angle as the suspension travels up and down and create fore/aft or left right pull on the sway bar and may wear the bushings faster. Also, you want the bar to be twisted in corners, not pulled side to side.
In properly designed race cars the sway bar links are very long, over a foot. Usually these bars are adjustable along the bars arm, the long end links makes this possible without undue stress on the bar or linkage. This helps the bar to function more predictably.
In tightening the end links, you want to squash the bushings as much as you can without causing damage to it during operation. How much that is, I don't know. The more squash you get the stiffer the bar is going to act. Quite a bit of sway bar stiffness can be lost in the links, especially if they are stock rubber and not very tight.
I have used the bolt tightness to tune the handling. If I get too much front stiffness, I back the nuts off about three turns each side. It can make a small difference in the front rear balance. A greater difference is achieved by swapping stock rubber bushings two at a time on each side to soften the front bar. This can be done to some rear bars too.
The GM manual calls for 8 foot pounds on the end link nut. I think the stock nut is 5/16", I think most aftermarket links have 3/8" bolts in them, a 3/8" bolt of average strength should not be torqued over 35 ft lbs or it would be damaged. So this puts our torque range between 8lbs min, and 35 lbs max.
I usually tighten the links by hand and watch the bushings swell a little, if they swell to the diamiter of the washers I feel I'm pretty close. It's probably about 10 to 15 ft lbs.
You can improve a stock bars (stock bushings) performance a lot by stuffing something around the bar in the frame mounts to compress the rubber more, and adding some washers under the nuts and tightening them.
David
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The older I get, the faster I was!
[This message has been edited by davidpozzi (edited 05-24-2000).]