There are few finer moments than the first time you wind out all the gears in your LS1-, LS6-, LS2-, LT1-, or TPI-powered ride. That glow can last a few weeks-even a couple of months-but fades once you wish you were a little quicker and faster. If you've been a rodder like me for 20 years, you can recall fondly and with some amusement how important it was to weld on some loud mufflers and immediately hit the local haunts. Now that I'm older and also more budget conscious (a few kids will do that to you), researching the best bolt-ons for the money is my number one priority when I start modifying a new car.

Now that the GM EFI scene is over 25 years old, the number of possible bolt-ons is in the hundreds. With the right combination of parts, the LS, LT, and even the TPI-powered cars have the potential to run 13s, 12s, 11s, and even 10s with internally stock engines. For our purposes, let's assume that LS1-, LS6-, and LS2-powered rides make between 290 and 350 rwhp stock, and run low- to mid-13s. Let's also assume that LT1-powered cars crank out around 245 rwhp stock and bust out high 13s at the track. And lastly, TPI cars make around 200 rwhp stock and run low- to mid-14s.

Let's start discussing the best-bang-for-the-buck mods under $100, $500, and $800 for LS1-, LS6-, LS2-, LT1-, and L98-powered cars. We'll note the price, average power gain, performance, and level of install difficulty. And after you pick up some of these goodies, make sure your ride is in a good state of tune before you start wrenching on it. We advise throwing in a new set of spark plugs, a fuel filter, and checking all your fluids. And of course, take all precautions when jacking up and working under your vehicle-always use jackstands and be safe! J

The author would like to thank Speed Inc., Thunder Racing, Carey's Custom Auto (Kyle Hiznay), and Sikora Precision (Chris Sikora) for their assistance with this article.

Best LS1-LS6-LS2 Bolt-Ons
Under $100

Slp Air Box Lid
This bolt-on should take about five minutes, and that includes three minutes to get another cold one. Aftermarket lids don't have the restrictive baffles and resonators of the OEM stuff, and swapping the lid in most cases just requires removing the factory IAT grommet and popping it into the new part.

Price: $99
Gain: 10 rwhp
Performance: .1 e.t. reduction, and 1-2 mph gain
Install difficulty: Easy

QTP Exhaust Cutout
For about the cost of three pizzas, you can buy an exhaust cutout such as the QTP. By running an open 'dump' you can free up some horses without spending a lot of money on a catback. You will need to have this cutout welded into your stock exhaust, typically in front of the rear axle.

Price: $45
Gain: 12 rwhp
Performance: .1 e.t. reduction, and 1-2 mph gain
Install difficulty: Hard unless you know how to weld


Under $500

Slp Off-Road Y-Pipe
Another good bang-for-the-buck would be this Y-pipe, which also eliminates factory catalytic converters. While not emissions legal in most states, this mod is worth some power and will turn heads at the strip.

Price: $299
Gain: 8 rwhp
Performance: .05 e.t. reduction and 1 mph gain
Install difficulty: Medium


ASP Underdrive Pulleys
Another tried-and-true bolt-on, the underdrive balancer pulleys free up horsepower while still charging up the factory system just fine. While not too hard to install, hitting the final torque spec will take some muscle unless you are using power tools.

Price: $269
Gain: 8 rwhp
Performance: .05 to .1 e.t. reduction and up to 1 mph gain
Install difficulty: Medium


SLP Ram Air
This is one of those mods that shines at the track, though the dyno gains are modest. This induction setup is a killer addition to LS1-powered 4th-gens, and is typically worth nearly a solid tenth and a 1 or more mph gain in the quarter.

Price: $169
Gain: 5 rwhp
Performance: .05 e.t. reduction and 1-2 mph gain
Install difficulty: Easy


Hooker Headers
Headers should definitely be in the must-have category for bolt-ons. Gen III mills can pick up gains of 20 rwhp or more from the addition of a good set of long-tube headers. It's hard to beat the bang-for-buck of some uncoated Hooker long-tube headers. Headers can take awhile to install, but most DIY'ers can knock out a set in an afternoon.

Price: $349
Gain: 20 rwhp
Performance: .2 e.t. reduction and 2-3 mph gain
Install difficulty: Hard

Nitto Or Mickey Thompson Drag Radials
Traction is the name of the game with drag radials. Air down the tires according to the manufacturer's guidelines, do a good burnout, and enjoy some hookage. Nittos work well for cars that see a lot of daily driver miles, and will last longer. The Mickey Thompson drag radials will wear out a lot faster but will out hook all other drag radials.

Price: $400 for two
Gain: N/A
Performance: .3 e.t. reduction and 1 mph gain
Install difficulty: Hard, unless you work at a tire shop

Random Technology Catback
Most catbacks will free up some horsepower, and give you a kick-butt sound to boot. While the power gain is mostly from running a lower-restriction muffler, going from 2.75-inch exhaust to 3 or more helps out too. Most DIY'ers can swap out a catback in a couple of hours, or longer if you try to take it out in one piece. The Random Technology catback features the best of both worlds: great price and great gains.

Price: $399
Gain: 15 rwhp
Performance: .05 to .1 e.t. reduction and 1 mph gain
Install difficulty: Medium

HP Tuners Software Package
Tuning options have come a long way over the last 10 years, and HP Tuners is a great option for the enthusiast who is prepared to do some research on how to best tune their vehicle. Being able to turn on your fans sooner, adjust air/fuel ratios, timing tables, and minimize torque management are just a few of the handy features of tuning software. In most Gen IIIs, horsepower gains are easily 10 rwhp to 20 rwhp depending on what other mods you have done to your car. Take precaution and do research before you start programming, since it's easy to get carried away. Saving a copy of your stock program is the first order of business.

Price: $499
Gain: 10 rwhp or more
Performance: .1 e.t. reduction and 1 mph gain
Install difficulty: Medium

Under $800

Nitrous Express Wet Kit
Expect 125 rwhp or more from this nitrous kit, which translates into e.t. drops of over a full second. Along with its high fun factor and great bang-for-the-buck comes great responsibility. Follow the manufacturer's instructions closely, as misused nitrous can damage engines and wallets. While there are some handy accessories for nitrous, like window switches and bottle heaters, you can get started fairly cheap.

Price: $609
Gain: 125 rwhp
Performance: 1.0 e.t. reduction and 10 mph gain
Install difficulty: Hard, unless you are handy with wiring

Yank Performance Torque Converter
Gen IIIs respond extremely well to aftermarket torque converters, and Yank has a great line of converters that range from mild to wild. The Yank Pro Thruster 4000 is a great strip converter, and is usually good for five tenths or more drop in e.t. at the track. If you can put up with a loose converter, think 4,400, but if you have an extensive commute or want to maintain somewhat decent gas mileage, focus on a 3,500 stall, which will still yield a three-tenths drop in e.t. Converter installs are very time intensive for the first-timer, so budget a day or drop it off.

Price: $799
Gain: N/A
Performance: .5 e.t. reduction and 1-2 mph gain
Install difficulty: Hard

Meziere Electric Water Pump
As efficient as late-model GM engines are, electric water pumps are still worth over a tenth at the track and some measurable ponies on the dyno. Veteran DIY'ers will typically wire the pump to keyed ignition since most of us would probably forget to turn the pump on until after the car has overheated. Some diehard rodders prefer to have the pump triggered manually so that they can cool the engine down after making a pass without running the engine. While not a hard install, the wiring takes some skill.

Price: $599
Gain: 10 rwhp
Performance: .1 e.t. reduction and 1 mph gain
Install difficulty: Medium

Best LT1 Bolt-Ons
Under $100

QTP Exhaust Cutout
For less than 50 bones, you can buy an exhaust cutout such as the QTP. By running an open 'dump' you can free up some horses without spending a lot of money on a catback. You will need to have this cutout welded into your stock exhaust, typically in front of the rear axle. Don't wear your Sunday best when opening it up, since you have to undo a few wing nuts underneath the car.

Price: $45
Gain: 12 rwhp
Performance: .1 e.t. reduction and 1 mph gain
Install difficulty: Hard, unless you have welded before

March Underdrive Pulley
Another tried-and-true bolt-on, underdrive balancer pulleys free up horsepower while still charging the electrical system. While not too hard to install, hitting the final torque spec will take some muscle.

Price: $88
Gain: 5 rwhp
Performance: .05 to .1 e.t. reduction and 1 mph gain
Install difficulty: Medium

Under $500

K&N Cold-Air Induction
While there are several notable air-induction manufacturers for the LT1, K&N is among the most popular and was frequently the best priced in our research. Expect between a one and two tenths drop in e.t., and a 47-percent increase in airflow. Installation is straightforward and should take about 10 minutes.

Price: $199
Gain: 15 rwhp
Performance: .1 e.t. reduction and 1 mph gain
Install difficulty: Medium

Hooker Catback
Most catbacks will help you net about 15 rwhp, and give you a kick-butt sound to boot. While the power gain is mostly from running a lower-restriction muffler, going from 2.75-inch exhaust to 3 or more helps out too. Most DIY'ers can swap out a catback in a couple of hours, or longer if you try to take it out in one piece. The Hooker catback is the best of both worlds-great price and great gains.

Price: $330
Gain: 15 rwhp
Performance: .1 e.t. reduction and 1 mph gain
Install difficulty: Medium

Crane 1.6 Roller Rockers
Swapping out the stock, stamped, 1.5 OEM rockers for a set of Crane self-aligning rocker arms is done for several reasons, however, the gain of 5-7 rwhp is why LT1 enthusiasts routinely suggest this swap as one of the must-dos. The other top reason is for increased valvetrain stability when turning the engines at higher rpm.

Price: $369
Gain: 7 rwhp
Performance: .05 e.t. reduction and .05 mph gain
Install difficulty: Medium

Meziere Electric Water Pump
Even though stock water pumps are efficient, electric water pumps are still worth over a tenth at the track and some measurable ponies on the dyno. Veteran DIY'ers will typically wire the pump to keyed ignition since most of us would probably forget to turn the pump on until after the car has overheated. Or, if you prefer, wire it to have the pump triggered manually to cool the engine down after making a pass without running the engine. While not a hard install, the wiring takes some skill.

Price: $219
Gain: 8 rwhp
Performance: .05 e.t. reduction and 1 mph gain
Install difficulty: Hard, since there is wiring involved

Nitto Or Mickey Thompson Drag Radials
Traction is the name of the game with drag radials. Air down the tires according to the manufacturer's guidelines, do a good burnout, and have your head snapped back. Nittos work well for cars that see a lot of daily driver miles, and will last longer. The Mickey Thompson drag radials will wear out a lot faster but will out hook all other drag radials.

Price: $400 for two
Gain: N/A
Performance: .3 e.t. reduction and 1 mph gain
Install difficulty: Easy for the tire guy

Under $800

Precision Industries Torque Converter
Look no further than Precision Industries' Vigilante line of torque converters for the LT1 engine. Their single-disc lock-up converters have helped propel many a bolt-on LT1 car into the 12s. Many LT1 enthusiasts recommend running a 3,200 stall with internally stock engines. While it's on the more difficult end of the scale for the DIY'er, this is a mod that can be done in an afternoon-or in about two hours by a professional.

Price: $699
Gain: N/A
Performance: .3 e.t. reduction and 1 mph gain
Install difficulty: Hard, unless you know what you are doing

Nitrous Express Wet Kit
Expect 125 rwhp or more from this nitrous kit, which translates into e.t. drops of close to a full second. Along with its high fun factor and great bang-for-the-buck comes great responsibility. Follow the manufacturer's instructions closely, as a poorly installed nitrous system can damage engines, your wallet, and your eardrums when the old lady hears about it. While there are some handy accessories for nitrous, like window switches and bottle heaters, you can get started fairly cheap.

Price: $585
Gain: 100 rwhp
Performance: .8 e.t. reduction and 9 mph gain
Install difficulty: Hard, unless you are handy with wiring

Best TPI Bolt-Ons
Under $100

Adjustable Fuel Pressure Regulator
Crane's adjustable fuel pressure regulator provides rodders with the ability to tweak the fuel curve, which can not only help increase horsepower, but even improve fuel economy. It's not unusual for most DIY'ers to bump up their base fuel pressure 5 psi once they have added most of the bolt-ons mentioned in this article.

Price: $69
Gain: 15 rwhp
Performance: .05 e.t. reduction and .05 mph gain
Install difficulty: Medium

March Underdrive Pulleys
March's underdrive balancer pulleys free up horsepower while still charging up the electronics. An easy install, save for the final torquing.

Price: $52
Gain: 5 rwhp
Performance: .1 e.t. reduction and 1 mph gain
Install difficulty: Medium

Thunder Racing Air Foil
Aftermarket air foils smooth out the air path by eliminating the dead space between the throttle blades. While hard to measure, this is one of those supporting modifications that's hard to pass up and only helps as your car makes more power.

Price: $47
Gain: 5 rwhp
Performance: .05 e.t. reduction and .05 mph gain
Install difficulty: Easy

Under $500

SLP Cold-Air Induction
Look no further than SLP for a great cold-air system. SLP designed this system for maximum performance by creating a more direct air path, and including a better-breathing, cotton-gauze air filter.

Price: $249
Gain: 10 rwhp
Performance: .1 e.t. reduction and 1 mph gain
Install difficulty: Medium

Hooker Super Comp Long-Tube Headers
While there are many options for the tuned port injection crowd, the Hooker long-tube headers provide the best overall horsepower gains as well as a substantial increase in torque. These headers are available coated and uncoated-the uncoated ones will cost less than $200.

Price: $185
Gain: 20 rwhp
Performance: .2 e.t. reduction and 2 mph gain
Install difficulty: Medium

Hooker Catback
Hooker exhaust systems are 100% mandrel bent and built to their high standards. This system utilizes their Aero Chamber mufflers, which provide major horsepower gains and a deep, powerful sound. This system gets the nod based on the gains and best average price.

Price: $300
Gain: 10 rwhp
Performance: .1 e.t. reduction and 1 mph gain
Install difficulty: Medium

MSD Ignition
While more of a supporting cast member in this ensemble, the venerable MSD ignition system increases spark, improves combustion, and improves throttle response for most TPI combinations. While spending upwards of $300 on an ignition box and a coil does not seem like a direct value, these mods are typically needed to support the TPI rodder's quest for e.t.'s in the 11s and 12s.

Price: $184
Gain: N/A
Performance: N/A
Install difficulty: Easy

Crane 1.6 Roller Rockers
Swapping out the stock, stamped, 1.5 OEM rockers for a set of Crane self-aligning rocker arms is done for several reasons, though the gain of 5-7 rwhp is why TPI enthusiasts routinely suggest this swap as one of the must-dos. Stock rockers are now 20 years old and were never designed for higher performance levels.

Price: $369
Gain: 5 rwhp
Performance: .05 e.t. reduction and .05 mph gain
Install difficulty: Medium

Nitto Or Mickey Thompson Drag Radials
Traction is the name of the game with drag radials. Air down the tires according to the manufacturer's guidelines, do a good burnout, and enjoy serious hookage. Nittos work well for cars that see a lot of daily driver miles, and will last longer. The Mickey Thompson drag radials will wear out a lot faster but will win a Pepsi challenge on which drag radial hooks hardest.

Price: $400 for two
Gain: N/A
Performance: .3 e.t. reduction and 1 mph gain
Install difficulty: Easy for the tire guy

Under $800

Holley Stealth Ram Intake Manifold
While the stock TPI intake manifold is out of breath around 4,500, the Holley Stealth Ram intake manifold can help an internally stock engine pull clean to 6,000 rpm. Gains of 20 rwhp or more make this a must-do mod. You'll need a set of Holley's fuel rails to complete this mod, and a set of new valvesprings are also recommended.

Price: $530 with fuel rails
Gain: 20 rwhp
Performance: .2 e.t. reduction and 2 mph gain
Install difficulty: Medium

Nitrous Oxide Systems Wet Kit
A long time favorite of the TPI crowd, this nitrous setup features a spray bar plate that mounts between the throttle body and the plenum. Gains are around 100 rwhp, with e.t. reductions of close to a second. As said before, nitrous is a demanding mistress and must always get a lot of attention. Make sure to run colder spark plugs and have a dependable fuel system.

Price: $549
Gain: 100 rwhp
Performance .3 e.t. reduction and 1 mph gain
Install difficulty: Hard, unless you have wiring skills

Precision Industries Torque Converter
Precision Industries' Vigilante line of torque converters has your TPI engine covered. Their single-disc lock-up converters have helped propel many a bolt-on TPI car into the 13s and 12s. Most TPI experts suggest a 2,800 stall speed for an internally stock TPI. While on the more difficult end of the scale for the DIY'er, this is a mod that can be done in an afternoon-or in about two hours by a professional.

Price: $699
Gain: N/A
Performance: .3 e.t. reduction and 1 mph gain
Install difficulty: Hard
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