Complete Guide to Lowering Options for Your Muscle Car, Hot Rod, or Truck
Take Your Ride to New Lows
Personalizing your ride means different things to different people Some want all the horsepower, while others want creature comforts, and yet others are more in tune with the bare necessities (and that can even include paint, or the lack thereof!). What is universally sought after by most, however, is that perfect stance. A perfect set of wheels and a spot on ride height is something that turns heads even before the turn of the ignition key.
There are multiple ways to get your hot rod or muscle car down low, be it if you’re looking for just a couple of inches of drop, or that scraping the road reflectors off the highway look. Whatever your lowering thoughts are we are here to explain the different lowering options available for your specific chassis and what their pros and cons are of each option, such as lowering springs vs coilovers. By the end of this buyer’s guide you’ll have a complete understanding of the options available to you so you can choose the best course of action to give your truck, hot rod, or muscle car the stance it deserves for improved looks and handling.
Is It OK to Cut Coil Springs?
We are not fans of cutting coil springs to alter ride height. We know people do it, so we wanted to address it in this buyer’s guide. Cutting coil springs will indeed lower your vehicle. Is it the right way to lower a vehicle? Some will say yes, others no. As long as enthusiasts have been modifying their rides people have been lowering them by cutting the springs down. If you are going to cut your springs it should only be for minor height adjustments due to corner weights and with a cut-off wheel, band saw, or other “cold” cutting method. Never use a torch to heat the springs or to cut the springs, as it will weaken the spring, and do not remove more than half of a coil. Extensive cutting will alter the spring’s rate, making for a harsh ride or even allow the spring to dislodge from the spring pocket over rough roads.
Pros
- Virtually free
- Easy to do
- Can be combined with dropped control arms or dropped spindles for an even lower ride height
Cons
- May require several tries to get your desired ride height
- Ride quality will be reduced due to the spring rate being stiffened. This will be a relatively small change when cutting 1/4 to 1/2 of a coil but will be noticeable when cutting one or more coils off.
- Not possible on springs with pigtails
- May require shorter shock absorbers
- May require modification to the suspension limiter or bump stop
- May cause adverse suspension geometry changes or bump steer issues if the springs are cut for large amounts of drop
Are Lowering Springs a Good Option?
While we can all agree that cutting coil springs does lower your ride height (and it is pretty much free), it is also not the best route to get the stance you’re looking for with a decent ride. This is where a quality set of lowering springs becomes the alternative that should be considered such as the Eibach lowering springs shown here. A set of lowering springs for your application are engineered to not only lower the vehicle, but maintain a firm, sporty ride in most instances. They are direct replacements for your stock springs and are usually not difficult to install, however they do only provide a certain amount of drop, which may not be enough for the look you are going for (which is why we suggest combining lowering products in some instances for the most aggressive drop while maintaining some resemblance of ride quality).
Pros
- Low cost
- Easy to install for most applications
- Spring rate is tailored to the application. Some springs are intended to improve handling with a stiffer spring rate and others are intended to maintain or improve ride quality.
- Older vehicles may need the springs replaced anyhow so it’s a killing two birds with one stone scenario
- Dropped coil springs can be combined with dropped control arms or dropped spindles for dramatically lowered stance
- Dropped leaf springs can be combined with a dropped axle for even lower ride height
Cons
- Ride height is not adjustable. Adding shims or cutting the spring is the only means of adjustment with coil springs. Leaf spring would need to have a leaf added or removed.
- Load handling capability may be reduced. This is especially a concern for rear springs on trucks.
- May require shorter shock absorbers
- May require modification to the suspension limiter or bump stop
- Limited in the amount of drop that can be achieved with springs alone
- May cause adverse suspension geometry changes or bump steer issues if too much drop spring is used
Are Drop Spindles Good?
A drop spindle is a spindle that has been designed to lower the front of a vehicle by raising the spindle’s pin the same distance. So, a 2-inch drop spindle will have a 2-inch raised pin height. What this means is the spindle, in all other specifications, works just like a stock spindle in the manner it is mounted to control arms/struts, tie-rod ends, and so on, but provides a lower ride height. Generally speaking, if the vehicle’s suspension is well designed to begin with (minimal bump steer, good turning radius, etc.) there will be no adverse effects or changes to the front suspension and how the car handles, yet you can enjoy the lowered ride height by simply bolting on the drop spindle, that is if one is available for your application.
Pros
- Medium cost level
- Does not affect suspension geometry
- Ride quality will not be changed
- Older vehicles with drum brakes can be upgraded to disc brakes at the same time
- Can be combined with dropped springs or dropped control arms for even more drop
- Bolt on replacement for stock spindles in most applications
- Does not require new shocks – stock length shocks will be used
Cons
- Some applications will have minimum wheel size and/or backspacing requirements due to tie rod end clearance issues
- Ride height is not adjustable
What About Drop Control Arms Then?
Much like a drop spindle, a drop control arm is designed to replace the stock control arm(s) with a revised component that will lower the vehicle’s ride height. This is done in several different ways, including relocated coil spring seats (deeper into the control arm) on lower arms, and offset mounting shafts with revised ball joint locations to correct camber on upper arms. Installation is usually like drop spindles in that you are simply unbolting the stock parts and replacing them with the lowering control arms. Also like the drop spindle you can combine components to achieve just the right stance for your ride. Also, much like drop spindles, applications can be a limiting factor. Most drop arms are for two-wheel-drive trucks, though we do offer control arms for some popular GM muscle cars with deeper than stock spring pockets to allow ride height adjustments when combined with lowering springs and/or drop spindles.
Pros
- Medium cost level
- Come with new ball joints and control arm bushings so if your stock components are worn out you will kill two birds with one stone
- Heavy duty tubular design not only functions well but also looks great
- Ride quality will not be changed
- Direct bolt on replacement installation
- Can be combined with drop springs or drop spindles for even lower ride height
Cons
- Reduced scrub line
- Ride height is not adjustable
Are Coilover Kits the Best Lowering Option?
A coilover shock system takes the suspension’s coil spring and shock absorber (or strut assembly in newer cars) and combines them into one component. This provides for compact packaging and helps with unsprung weight some. But most importantly coilover shocks allow for an easy to adjust suspension system whereas you can often adjust the shock for rebound only, or rebound and compression, plus swap out the coilover spring for different spring rates that affect ride quality and handling. However, the most important aspect of the coil-over shock system for most is the ability to quickly adjust vehicle ride height simply by adjusting the coilover spring’s threaded lower spring perch up or down the threaded shock body. This is accomplished by hand or with a simple spanner wrench right on the car in minutes.
Pros
- Medium cost level
- Adjustable ride height
- Various spring rates are available to fine tune your ride quality or handling characteristics
- Available with adjustable shock valving
- Bolt on kits are available for a wide variety of applications
- Can be paired with drop spindles for even lower ride height
Cons
- Applications with factory leaf spring suspension require a complete suspension kit for use with coilovers
- May require modification to the suspension limiter or bump stop
- Limited in the amount of drop that can be achieved with coil-overs alone
- May cause adverse suspension geometry changes or bump steer issues if too much drop is used
Can You Lower a Solid Axle Hot Rod?
So far, we’ve been discussing lowering options for coil spring applications, be it solid rear axle setups or independent front suspension (IFS) configurations. For many hot rodders though the straight axle front suspension, popularized on such platforms as the 1928-1941 Ford cars, 1948-1960 Ford trucks, and 1947-1954 Chevy cars, is still their preferred front suspension. And yes, they can be lowered. The two ways you can lower a straight axle front end is with a drop axle or drop leaf spring package. Drop axles are direct replacements for the stock height axle that are engineered with a higher king pin location, like a drop spindle. Similar to a drop control arm, you can retain the stock spring (in this case a transverse leaf) to maintain good ride quality and load capacity.
Pros
- Medium cost level
- Direct bolt on replacement for the stock axle
- Retains the stock ride quality
- Maintains original load capacity when used with stock springs
- Can be combined with drop leaf springs for an even lower ride height
Cons
- Most require dropped tie rod ends or custom steering linkage
- More expensive than drop leaf springs
- Installation is more extensive than drop leaf springs
Is a Rear Axle Flip Safe to Do?
Most hot rods and muscle cars utilize an underslung leaf spring setup, where the axle is rides on top of the leaf spring pack. The only way to lower these is with different leaf spring rates or with mid- or reverse-eye spring ends or lowering blocks (more on those below). However, for truck applications we generally find their axles to be overslung, with the leaf spring pack on top of the axle assembly. In this situation relocating the axle to reside on top of the spring pack utilizing a leaf spring flip kit effectively lowers the rear of the truck anywhere from 5 to 7 inches (the sum of the axle diameter and spring pack thickness) with simply hand tool work in most cases and does not diminish ride quality or load capacity. Popular kits include shock relocation brackets where needed and you can go even lower by combining the axle flip with shorter shackles, lowering blocks, or drop springs.
Pros
- Low to Medium cost level
- Retains stock load capacity
- Can be used along with lowering blocks, drop shackles, or drop springs for even lower ride height
Cons
- Requires a C-notch kit to gain clearance between the axle and the frame
- Requires removal or relocation of bump stops
- Requires shorter shocks or shock relocation brackets (if brackets are not included in the kit)
What Suspensions Do Lowering Blocks Fit?
Leaf spring lowering blocks are used on solid rear axles suspended by leaf spring packs, with the sole coil spring rear suspension application that can take lowering blocks being the 1960-1972 Chevy trucks. The axle must be underslung (spring under the axle) for lowering blocks to be fitted between the leaf spring pack and the spring perch on the axle tube (otherwise it would actually raise the vehicle). So, for muscle cars and hot rods this is simply a matter of unbolting the axle, raising it up, and inserting the leaf spring lowering blocks. For overslung applications you’ll have to do an axle flip first.
Pros
- Low cost
- Available in a variety of heights to dial in your preferred ride height
- Maintains factory ride quality and load capacity when used with stock springs
- Easy installation
Cons
- Requires longer U-bolts (not always supplied with the blocks)
- May cause wheel hop on acceleration, especially if using two inch or taller lowering blocks
Can You Change the Leaf Spring Hanger?
Leaf spring hangers are commonly found in truck applications and other vehicles with full frames. They are usually riveted to the frame and provide a pocket for the front leaf spring eye to mount and pivot from during suspension movement. You can find some applications available separately, but most drop hangers are found in complete rear suspension lowering kits or in a kit with a set of lowering shackles (more on those next). Typical leaf spring hanger drops are in the two to four inch range.
Pros
- Medium cost level
- Retains stock ride quality and load capacity
- Commonly used along with drop shackles for even lower ride height
- Can be used along with an axle flip for extreme drops
Cons
- Alters the pinion angle slightly unless used along with drop shackles
- Installation typically requires cutting or drilling out rivets that fasten the factory spring hangers to the frame
- More expensive and harder to install than drop shackles if a small amount of drop is desired
- Ride height is not adjustable
Are Leaf Spring Shackles a Good Option for Lowering?
Many people associate shackle kits with raising the rear of a car, popularized in the 1960s and 1970s to allow room for larger tires in the rear of a muscle car (along with a set of air shocks too!). However, you can go in the opposite direction by using lowering leaf spring shackles as well. They are usually paired with lowering spring hangers, but you can do just the leaf spring shackles if you don’t want to deal with drilling/grinding out all those rivets that mount the hangers onto the frame. Typical leaf spring shackles are bolt-in replacements for the stock parts and will lower the rear of your vehicle approximately two inches.
Pros
- Low cost
- Easiest to install of any leaf spring lowering product
- Retains stock ride quality and load capacity
- Many have dual holes to adjust the amount of drop it will provide
- Commonly used along with drop leaf spring hangers for even lower ride height
- Can be used along with an axle flip for extreme drops
Cons
- Alters the pinion angle slightly unless used along with drop leaf spring hangers
Can Torsion Bar Spring Vehicles Be Lowered?
Enthusiasts might equate torsion bar spring front suspensions with Ma Mopar, but the Dodge boys aren’t the only game in town that used torsion bar spring front ends. You’ll find these springs used in both GM and Ford truck applications too. A torsion bar spring works in a similar fashion to a sway bar, in that that the spring function is derived from the twisting motion of the bar itself, with one end connected to the lower control arm and the other end fixed to the vehicle’s frame with a torsion key. An adjuster pushes on the torsion key, providing a certain amount of twist in the torsion bar. You can often get a small amount of lowering (perhaps up to 1-inch) simply by loosening the key, but any further you will need to replace the factory torsion bar keys with specific lowering keys that allow further drop.
Pros
- Low cost (or free if you need just a little drop)
- Simple installation
- Retains stock ride quality
- Adjustable ride height
- Can be combined with drop spindles for an even lower ride height
Cons
- Limited to approximately 2” of drop
- Requires modification or removal of bump stops
What About an Air Bag Suspension System?
Early on air bag suspensions kind of got a bad rap that they were only good for one thing: laying frame. Sure, hot rods, muscle cars, and especially classic trucks, look sweet slammed to the ground, but an air bag suspension can do so much more. Thanks to the onboard air compressor, level sensors, and other features, you can have on-the-fly suspension adjustments to sprung weight/cargo loads, road conditions, and more. On the highway? Drop it down and maybe save some gas. Going up a steep offset driveway? Add some air and raise the front end to prevent damage. No longer do you have to pick a fixed ride height and live with it. Air suspension suspensions are dynamic and allow you to run whatever ride height you wish and can be changed with a few button pushes right from the driver’s seat.
Pros
- Ride height is adjustable even while driving the vehicle
- Ability to raise the vehicle to clear obstacles such as a steep driveway
- Smooth ride quality
- Heavy load rated air springs are available which allow for towing and hauling heavy loads
Cons
- High cost
- Extensive installation process
- In addition to air springs you will also need mounting brackets, hoses, fittings, air tank, and controls
- Vehicles with factory leaf spring suspension may require a complete suspension kit, such as a 4 link
- Handling performance may be reduced compared to some traditional spring suspensions
