DEPO Headlights FAQ: GX470, 350Z, IS300 Fuel Pump, Cast Iron Radiators & Blown Head Gasket

I coordinate rush orders at an aftermarket automotive parts supplier. When a shop calls at 4:45 PM because a bumper is off and the headlight does not fit, I'm the one already looking up stock numbers. After handling more than 200 rush orders in five years, I've learned that the difference between a good order and a bad order is almost never brand loyalty—it's fitment confirmation and honest lead times.

Here are the questions I answer most, plus the one nobody asks until the diagnostic is already painful.

• Are DEPO headlights worth it?
• Depo GX470 headlights: what's the deal with AFS?
• Depo headlights 350z: early or late model?
• How do I know if my IS300 fuel pump is failing?
• Is a cast iron radiator better for a vehicle?
• How do you know if you have a blown head gasket?
• When is an extra shipping charge actually worth it?

Are DEPO Headlights Worth It?

Here's the thing: DEPO is not a premium OEM brand, but it's not a mystery box either. I've stocked DEPO lamp assemblies for more than five years, and the housing quality is predictable. That sounds boring, but in a rush order, predictable is gold. With no-name lights, you're gambling on the mold, the UV coating, and the wiring connector. With DEPO, the main question is always the part number and the model-year split. For a normal daily driver or collision repair, DEPO is my default answer. If someone needs a show-quality projector retrofit, maybe not—that's a different conversation.

Because DEPO comes from a stamping and tooling background, the metal brackets and mounting points tend to be more consistent than brands that only make plastic. (They do sometimes have a slightly slower catalog ship date than the listing claims. I don't know why. My best guess is that the inventory systems lag by a day. The fix is simple: call and confirm before paying for expedited shipping.)

Are Depo GX470 Headlights a Direct Fit?

Mostly, but the first rule when someone asks about gx470 depo headlights is to check the AFS option. The Lexus GX470 came with Adaptive Front Lighting on some trims. AFS headlights have a leveling motor and a different connector. If you install standard Depo GX470 headlights on an AFS-equipped car, you might get a bulb that works and a dash warning that won't go away.

So the part number needs to match. After that, check the brackets and clips. In March 2024, I overnighted a GX470 headlight to a body shop. The housing was fine, but the original clip cracked when they transferred it. The extra clip wasn't included. We ended up zip-tying the housing to the mount while the factory clip shipped overnight. The car left on time (barely), but the lesson stuck: ask if the mounting clip and retaining hardware come with the housing. This is the question that saves a second day.

Are Depo Headlights for the 350Z Direct Replacements?

People ask about depo headlights 350z compatibility every single month, and the first thing I ask is: 2003-2005 or 2006-up? Nissan changed the nose and lamp mounting for the 350Z after the facelift. A lamp that fits a 2004 car will not line up on a 2007 car. The electrical connectors look similar, but don't trust 'looks similar.'

Second, check whether the car was originally HID or halogen. If you put halogen projectors in a car that expects HID, you'll have a beam that's too dim. If you put HID bulbs into a halogen DEPO housing, you'll blind everyone and scatter the light. The DEPO 350Z catalogue separates these. Use the VIN or the original ballast part number to verify. This takes two minutes on the phone and can save an entire day.

I've never fully understood why the connectors are so close between the generations. It feels like a trap. But the cure is the same: don't assume.

How Do I Know If My IS300 Fuel Pump Is Failing?

The is300 fuel pump sits in the tank under the rear seat, and the car will usually warn you slowly before it quits. The typical signs: long cranks after the car sits, a stumble when you're on the throttle, and a fuel pressure reading that drops under load. If the pump is completely dead, you'll hear no prime when you turn the key to the ON position. But listening for a whine isn't enough—a failing pump can still make noise without making pressure. The reliable way is to install a fuel pressure gauge and watch it during a road test. On a stock IS300, you mainly need a quality replacement, not a big upgrade. Cheap universal pumps fail in less than a year, which is worse because you're pulling the tank twice.

Is a Cast Iron Radiator Better for a Vehicle?

Honestly, the phrase 'cast iron radiator' is mostly a cross-catalog mystery to me. I'm not 100% sure why it shows up in automotive searches; my best guess is that it comes from industrial heaters, steam boilers, or vintage engines. For a car or truck, cast iron is a terrible radiator material for most purposes. It holds heat instead of shedding it, adds a significant weight burden, and has slower coolant flow than an aluminum core. Aluminum radiators are lighter, cool faster, and are much easier to repair or recore.

If you're restoring a very old machine and the original spec was cast iron, that's a different conversation. You need a pattern and a foundry, not a parts catalog. But if a supplier tries to sell you a cast iron radiator for a daily driver, ask for thermal performance data. If they can't explain why it's better, they're selling you a word, not a solution.

How Do You Know If You Have a Blown Head Gasket?

You don't need to start by pulling the cylinder head. Do these checks in order:

1. Pull the dipstick. If the oil looks like a chocolate shake, stop. That's coolant in oil.
2. With the engine cold and the radiator cap off, start the engine and watch the coolant. Constant bubbles that grow as it warms mean exhaust gas is going into the cooling system.
3. Run a compression test. Two adjacent cylinders reading noticeably low is a classic sign of a blown head gasket.
4. Use a combustion leak test block. The fluid changes color if combustion gases are present in the coolant. It costs around $20 and is far better than guessing.

There's something satisfying about catching a head gasket before it becomes a cracked head. If the test says yes, don't drive it. A short trip across town can turn a $1,500 repair into a $4,000 repair. I know the temptation to say 'probably make it' is strong. I've answered the phone after a few of those decisions, and the diagnosis was never the expensive part—the engine replacement was.

When Is the Extra Shipping Price Worth It?

Look, I'm not going to tell you to rush every order. Sometimes 'next day delivery' is on the truck waiting for it to get back to the warehouse. But the idea that 'cheaper is better' fails under deadline pressure. In March 2024, a shop paid $46 extra to get a Depo GX470 headlight by 10:30 the next morning. The cheaper option would have arrived two days later, which meant another day of rental car fees, a disappointed customer, and a reputation hit. It took me about 3 years and dozens of wrong orders to understand that certainty has a price, and it's often a bargain.

The only condition: confirm the product is physically in stock before paying a rush fee. A guaranteed label on a backordered item is false certainty. That's the thing I check first now. If they can tell me the shelf location or the outgoing box count, I feel better. If they say 'probably' on a rush order, I treat it as no.