By definition, a diesel motor is an extreme environment that’s required to produce tremendous power and especially torque. They tend to run longer and hotter than gasoline motors, and putting these engines through racing events can really add to the stress.

One area that’s especially susceptible is the fastening of components. From connecting rods to heads to harmonic balancers, the severe vibrations of a diesel call for hardware that can put up with the abuse; that’s where ARP Bolts has answered the call.

Still, there are plenty of questions that get asked of ARP all the time. We spoke with Chris Raschke to find out what a few of them were, and gain some solid answers as well.

The first question is: Are ARP’s bolts going to increase clamp load? Are they better than a stock bolt? The answer is, undoubtedly yes. “Our stud kits offer increased clamp load when properly installed,” said Raschke. “All of our diesel kits use ARP2000 bolts, which are rated at 220,000 psi tensile strength. They’re also reusable, unlike most factory torque-to-yield bolts.”

The second question asks, “Where should I apply lube?” To this, Raschke recommended: “Put light engine oil into the block, or you can use our Ultra Torque lube there if you want. But make sure the washer is installed dry and clean. The lube will go onto the threads and bearing surface of the nut.”

Another question that Raschke hears constantly relates to the enigmatic “425” bolt. Raschke has been to several drag racing and sled pulling events and had people come up to him asking about this 425 bolt, asking how it ranks against the New Age 625, which is a legitimate product made by ARP.

“I figured out that there is no such thing,” he said. “It’s actually just a made-up term applied to our ARP 2000 bolts, and people claim it’s above the ARP 2000 so they pay more. We’re not sure where the term came from, but it’s a misconception.”

Custom fasteners are another area of inquiry for ARP. Raschke states that one-off designs are possible, but will take time. “A special, custom-made stud will be made here in the USA, but will take about eight to fourteen weeks,” he said. “Most of our custom work goes toward sled pullers, guys who have Caterpillar C15 motors. They need to have a lot of custom parts.”

ARP 2000s work great for normal diesel vehicles. New Age 625s are better suited for extreme diesel applications.

Finally, many enthusiasts wonder about making the leap from ARP 2000s to ARP 625s. To that, Raschke simply suggested that owners make sure they have their vehicle dialed in before making the decision. “We want you to have the right combination of parts, from turbos to cooling to exhaust,” he said. “We’ll recommend that you install to our specs, but generally, you can use ARP 2000s all day long, and 625s to keep things under control if the build is more radical.”

For more on ARP, head to the company’s website and Facebook page.