The Stovebolt Site Forums The Shop Area Driveline LOWERING QUESTION

I've been down this road before, and will probably go down it again, but lowering is a two-edged sword. Sure, it lowers the center of gravity for better handling (cool in a sports car, for a truck, maybe not the point) and it normally makes the vehicle look better.

But the drawback is you lose the range of movement on your suspension (suspension travel). Sure, you can put just as stout lowering springs, but you lose suspension travel, which means you are more likely to bottom out on the suspension stops or frame. Once the suspension is at the travel limits, it is no longer a suspension, you are driving a wagon.

Folks try to make up for the suspension travel issue by putting in higher spring rates (stiffer springs). This deteriorates the ride quality. This is why 46 talks about options to produce variable-spring rates. (Off-road folks do this all the time with double coil springs stack-mounted on one suspension point.) They work on the principle of a softer spring rate until the suspension compresses so far, then the spring rate goes up. Unless done right, this still can result in a "BAM!" kind of ride. And it is done to try to solve the problem lowering created.

So theoretically you can get a lower truck with the same cargo capacity, but to do so without riding on the suspension limits, you must suffer with higher spring rates (harsher ride) or invest in some variable spring rate technology. But you still have the same issue of less suspension travel, which you always prefer more of, not less.

Here's a math example of loss of suspension travel: say the stock suspension has 10 inches of travel and you lower 3 inches. Now, unless you have done something else, you only have 7 inches of travel. Let’s say that the stock suspension could take a ton load and it would settle down 5”. It still had 5” of travel. With the lowered setup, you have reduced that to only 2” of travel. The same bump in the road now has a greater potential for a negative “impact”.

Now, if you change the suspension mounting points, the loss of suspension travel argument can be made to go away, but then at some point you are likely into sheet-metal modifications to keep your tires out of your fender wells.

Lastly, lowering can impact, for a unequal-length A-arm independent front end (GM trucks after 1960), the suspension alignment. Normally you will have excessive negative camber, toe-in (assuming tie-rods in front of the spindle), and a potential for bump-steer. Some of this can be corrected via re-alignment, but without lowering the steering-box you may still have some. Of course this does not apply to the straight axle front end of your '55.

All of this doesn’t mean lowering is a bad thing, but just some comments around your expectations. It is not a “have your cake and eat it too” situation. Of course moderation applies—a minor lowering has less negative impact than a slam into the weeds.

Just some thoughts about the theory of it --like many other things, in practice it becomes much more subjective. I've been in lowered vehicles that are just a pain and nothing else, and others where I was surprised at how well it all worked. I suggest get some opinions of folks who have already done specifically what you contemplate doing.