5 Discreet Modern Upgrades For Classic Cars

There are an infinite number of paths before you when you take on the project of fixing up a classic car. If you plan to enter it in competitions and will be judged on the faithfulness of your restoration, original equipment manufacturer (OEM) and new old stock (NOS) parts are the only way to go. But these projects also present opportunities to add modern upgrades which make classic cars safer or more comfortable, powerful, and/or fuel efficient. If your goal is to have a fun and eye-catching daily driver, a restomod (part restoration, part modification) is the way to go.

There isn't a single change you can make to a classic beyond bone-stock parts swaps that will escape the eyes of purists at car shows, but some of the upgrades you can make will be hidden from all but the most obsessive enthusiasts with an overly critical eye and too much time on their hands. Here are a few improvements that will make your classic more fun for you and should add to its real-world value.

One of the simplest upgrades you can do on a classic car is to replace the old radio unit with one that supports Bluetooth phone calls, digital media, and USB smartphone charging. You don't have to sacrifice the vintage look of your classic, though. Head units are available from vendors like Retro Manufacturing and Classic Car Stereos that mimic the look of the original stereo units on many classic cars. The unit pictured above from Retro fits 1947-53 Chevy trucks and features Bluetooth 5.0 technology with an external microphone for phone calls, a 1/8 inch auxiliary input to play music, an AM/FM tuner with 30 presets, and a 275-watt amplifier. 

You can also peruse the Crutchfield website for more retro radio options, including this unit for 1960s and '70s Ford F-series pickups and Bronco models. It includes an external microphone, AUX input, and two USB connectors for charging and playing audio from your iPhone or Android device. Crutchfield also sells the wiring harnesses and dash plate kits you'll need to make the installation easy and clean.  

A subtle under-the hood upgrade that will make your car more driveable, particularly in cold weather or when climbing hills, is swapping out your primitive carburetor for an electronic fuel injection system. Holley's Sniper line of EFI systems can be installed in a wide variety of classic cars and trucks, and many of them can be mounted to your vehicle's stock intake manifold and be used with the original air filter. Most Sniper EFI units are available in a master kit that includes fuel hose, filters, an inline fuel pump, and fittings to return excess fuel to the tank. Many are styled to give a retro look and also contain kickdown linkages to connect to your transmission for smooth downshifts under hard acceleration.

Holley's Terminator Stealth systems are built to replicate the look of the stock carburetor on many classic vehicles, and provide the same features and easy installation process as their Sniper kits. Similar EFI kits are available from Fitech and Edelbrock as well.

For a quick and relatively easy performance boost for your classic car, consider replacing the stock exhaust manifold with a set of high-flow headers. Headers are generally made of lighter metals than stock manifolds, allowing you to shed a few pounds from your car's weight. Headers also route exhaust gases to your catalytic converter and tailpipe along a less restrictive path than the stock configuration. The reduction in backpressure throughout the exhaust system allows your engine to breathe more freely, leading to a horsepower increase. 

Hedman Headers are available for a variety of classic Ford and GM vehicles, and Headman also sells header kits that will work if you're planning an LS engine swap. Summit Racing sells headers for hundreds of classic cars and trucks, including their house brand kits as well as others from the likes of Hooker, BBK, JBA Performance, Hedman, Doug's Headers, and Flowtech. 

You can always opt to swap out your classic car engine for something more modern, but engine swaps aren't for the faint of heart. Instead of replacing your engine, consider adding a turbocharger instead. Turbochargers capture your engine's exhaust gases, compress them, and return them to the intake side, allowing the fuel to burn more efficiently. 

This can lead to power increases of as much as 40%, although you might have to start using premium fuel in your car after installing a turbocharger. Upgrading your engine from natural aspiration to a turbo also requires a few extra modifications beyond adding the turbocharger. You'll need at least a new exhaust manifold and some tubes and hoses to route the exhaust gases and compressed air, and you'll probably also have to modify your fuel delivery system for your car to run properly. Sometimes all you need is a new fuel pressure regulator, but some turbo upgrades also require new injectors, lines, and/or a higher capacity fuel pump.

Another modification you can make to many classic cars that will be invisible to most casual observers is converting its drum brakes to discs. Drum brakes slow the wheels via outward pressure from brake shoes on the inner surface of the drums, and were the standard for decades before disc brakes became more common. Disc brakes use calipers to squeeze the brake rotors, which are mounted to the wheel hubs. Disc brakes usually perform better than drum brakes, particularly in wet weather conditions. 

Disc brakes also dissipate heat better than drum brakes, and are less likely to lock up during panic stops. Conversion kits typically include rotors, calipers, shims and hardware, emergency brake cables, and hydraulic components. You can find drum-to-disc upgrade kits for many classic cars at Summit Racing, Jegs Performance, and Speedway Motors.