How To Convert A Full-Size GM Truck From 6- to 5-Lug

The 1999-2007 GM Silverado and Sierra pickups are very popular these days. With LS power under the hood, they’re pretty capable vehicles too. And that’s one reason we see more and more of these trucks at the drag strip. The only gripe we have about this vehicle is why GM decided to go from the five-lug combination in the previous model to a six-lug configuration on these trucks? And while companies do make six-lug racing wheels now, you’re very limited to just a handful of styles. The problem for us is we wanted more options to set our truck apart from the crowd. So ultimately, with the help of 1320 Wheels and Moser Engineering, we decided to perform a five-lug swap on our 2000 Silverado to give us a more extensive wheel selection.

Here’s a picture of everything we needed to convert the front and rear of our 2000 Silverado to 5-lug.

1320 Wheels Five-Lug Conversion

After we decided to do a five-lug swap, we reached out to Derek Hopwood of 1320 Wheels. The company specializes in five-lug conversions for the 1999-2007 and 2007-2019 Silverado/Sierra trucks and the Trailblazer SS. For the front, 1320 Wheels starts with new Timken hubs. Then, the studs are removed before they are machined to accept a 5×4.75-inch bolt pattern. This common bolt pattern among GM cars will give us a wide variety of wheels to choose from in the future. And since the factory brake rotors will no longer fit with the new pattern, we ordered a set of cross-drilled 13-inch and had 1320 Wheels modify them for us. “The only thing we’re essentially changing on the vehicle is the bolt pattern. So, any rotor made for that vehicle will work,” Hopwood explained. “The rotor will just need to be re-drilled to the new pattern. We offer standard replacement factory re-drilled rotors with our kits. We also offer a rotor redrill service for the guys who have aftermarket rotors and brake kits.” The company also offers a rear solution for these trucks, if you’re interested in using the stock axle.

We purchased the front wheel conversion from 1320 Wheels and had them convert the brake rotors to 5-lug as well.

Moser’s Custom Axles Program

With new parts on order for the front of our Silverado, we quickly turned our attention to the rear of the truck. Since we already have a Moser Muscle Pak bolted in, we made a call to the company to get new rear axles and rotors on the way. 

Moser manufactures all of their axles in the US, which allows them to offer a two-day turnaround after an order is placed. Jeff Anderson, Marketing Director of Moser, said, “From the very beginning, we have offered a standard two-day turnaround on all of our custom-made alloy axles. This service has fueled our record growth through five different decades and three generations of the Moser family.”

Moser had the rear axles to our door in just a matter of days after we order them for our Muscle Pak Fab9 rearend.

This speedy service is excellent for racers who might need a set of axles for a race. In fact, Greg Moser started the company because there was always a long wait on axles in the 1970s and 1980s. He became fed up with missing races while waiting on axles and decided to make sure he or his friends didn’t miss out anymore. 

“Greg designed a manufacturing process using his knowledge gained from running a large forging company in Indiana, “Anderson explained. “He used his lessons learned in the steel industry and turned it into a very successful and profitable business model. The company also quickly became a way to fund his hobby of drag racing. Greg always made sure everyone knew this company was to be a fun place to work and made sure his employees never lost sight of why the turnaround time was important.” 

Moser can make any axle you need, from a custom length 40-spline Pro Flange race axle to a basic custom length c-clip axle with a custom bolt pattern, and it never affects the standard two-day turnaround. However, if you need it quicker, Moser can help you out there, as well, even with custom orders. 

“We now offer a one-day turnaround for a charge, and some people can’t imagine us making a completely custom-made-to-order axle that fast.” Anderson continued, “They often assume we have axles laying around made in different lengths with splines already on them, and we just cut them to size, and that couldn’t be further from the truth. Every single axle ordered is made and cut to the exact custom length the day it’s ordered before it’s ever splined or drilled for the bolt circle.” 

Another fantastic thing about Moser’s axles, as we mentioned before, is that they are made with domestic steel and forged in the USA. They even do their heat treating in their 100,000 square foot facility in Portland, Indiana. Anderson said, “This, along with a corporate policy of maintaining a large inventory of goods, is why we haven’t experienced a lot of the issues other manufactures have experienced lately.”

If You Don’t Know

If you’re unsure what axles you need, Moser’s website will walk you through the process covering all of the bases, or you can download an order form. If you still need help, give Moser’s tech support a call, and they will make sure you get what you need. Fortunately for us, they had a record of our Muscle Pak rearend, so we didn’t need to measure anything or even count the splines. As promised, the Moser axles and Wilwood rotors showed up a couple of days later with the 1320 Wheels hubs right behind them. 

Converting The Front To Five-Lug

When asked how the conversion is to install, Hopwood said, ”The installation is pretty simple. A floor jack and a basic socket set can get the job done. If you can change your brakes you can install the conversion.”

Replacing the factory front 6-lug hubs was easy. We removed three bolts and then reinstalled the 1320 Wheels 5-lug hubs, rotors, and brake calipers.

The first step for the front end was to remove the front brake calipers and rotors. Then, with the factory components out of the way, we unbolted the three bolts holding the hub in the spindle. After that, we installed the 1320 Wheels hubs, reinstalled the rotors and brake calipers. We also threw in a new set of brake pads while everything was apart before torquing everything to OEM spec. Converting the front to five-lug was a simple task that only took about an hour. But would the rear be just as easy? 

Here’s a picture of the front with the completed 5-lug conversion. Now we need to do something about those ugly brake calipers.

Converting The Rear To Five-Lug

Removing the brakes and axles from the Moser Muscle Pak was a walk in the park and only took a few minutes.

Like the front, the first step on the rear was to remove the brake caliper and then the rotor. With these two items out of the way, we were then able to unbolt the axle-bearing retainer. To make access easy, Moser machines a hole in the axle flange so that a socket can pass through the opening to get on the nut. After we loosened the first one, we rotated the axle around until all four nuts were off. We then removed the retaining clip and slid the axle out of the Fab 9 housing. Next, it was time to go back together with the new parts from Moser, and the process was as simple as it sounds. Because they already knew what we had, there were no surprises with the replacements. The axles slid right back into place effortlessly, as did the Wilwood rotor hats and calipers. With everything tightened back up, we were done. 

With the 6-lug axles out of the way, we reinstalled the Moser 5-lug axles, Wilwood rotors, calipers, and we were done.

The five-lug conversion on this truck was a breeze. The parts fit together perfectly, and the entire process took us about two hours from start to finish. With our five-lug conversion complete, it’s time to do some measurements and order a set of wheels and tires for the Silverado. The only problem now is that we have entirely too many choices to pick. However, RC Components and Mickey Thomspon are on our list, so stay tuned.  

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About the author

Brian Havins

A gearhead for life, Brian is obsessed with all things fast. Banging gears, turning wrenches, and praying while spraying are just a few of his favorite things.
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