Pro Street, Pro Stock, Pro Touring, rat rod, tuner, West Coast Kustom, and low-rider; all have their place, but few have the provenance of the traditional Street Rod. While most of these styles are fairly ill-defined, the National Street Rod association sets some very specific requirements, namely that the car be 1948 or older and that it be modified with a more modern engine, transmission, chassis and/or interior refinements.
1. Begin with any car produced during or before 1948. Three and five-window Ford and Chevrolet coupes are popular, but may be a bit too popular for those who want their car to stand out in a crowd. Dodges and Studebakers are a bit outside the mainstream, and there’s nothing to stop you from making a street rod out of an old Daimler-Mercedes, Nash, Stanley Steamer, Dymaxion (replica), Buffalo Electric or any other off-brand car that you don’t often see given the Street Rod treatment.
2. Replace the frame and chassis with a more modern one. This goes right to the heart of the Street Rod movement, and your choices are only as narrow as your budget. You could take the junkyard approach by using a full-frame chassis from a pick-up or a car (ex: Chevrolet Caprice, Ford LTD), or you could purchase a pre-fabricated frame if you have a popular chassis. The highest-dollar and highest-return approach is to have a chassis custom-built out of steel tubing.
3. Install a modern suspension and braking system. The chassis you choose will determine your suspension options, but you should consider using a high-performance air-bag system that will allow you to custom-tailor or ride-height, ride-quality and performance settings as the situation dictates.
4. Power the car with your drivetrain of choice. The selection here is endless, as are the potential complications and chassis-compatibility issues. While the small-block Chevrolet/automatic transmission combo was once almost the default choice for most street rodders, no one’s impressed by a small-block these days. More avante garde builders might opt to replace the car’s original engine with its modern equivalent. For instance, a four-cylinder Model T might get a turbocharged Ford EcoTec four, a V16 Caddy might get a pair of Northstar V8s welded end-to-end. If you’ve unlimited cash, you could probably find a way to squeeze a Bugatti Veyron W16 into a 1938 Type 57.
5. Upgrade your interior to modern standards. There’s as much variation to interior design as to exterior. You could go with a pared-down race-car look if you wanted to, but modern street rods typically have luxury-car grade interiors. Look to such marques as Aston Martin, Bugatti, Mercedes and Rolls Royce for inspiration on interior materials and design essentials.
6. Finish your car with the right set of wheels and tires. The right stance can make or break your car’s entire look, so put a lot of thought into wheel/tire selection. Traditional Street Rods based on Ford and Chevy coupes were something of a precursor to the Pro Street style in that they used very large rear tires and skinny fronts. However, your car needn’t look like a dragster to be a street rod. 15-inch rims are the conservative choice, but you might be able to go as large as 19-inch fronts and 20-inch rears on the right car without making it look like a cartoon. It’s all about proportion; 20-inch rims might look right on a massive Nash Motors Airflyte, but they could look a bit vulgar on a 1938 BMW 328 Roadster.