The 1973 MGB featured on this episode of "Jay Leno's Garage" is responsible for keeping many of its kin on the road. That's because it serves as a testbed for parts supplier Moss Motors. Robert Goldman, chairman of Moss Motors, joined Jay Leno to discuss the car and its role with the company.

With a production run spanning two decades, the MGB is one of the most popular British sports cars of all time. The MG brand survives today under Chinese ownership, but primarily sells sedans and crossovers now. While time has inevitably removed some cars from circulation, the MGB still makes up a sizable portion of Moss Motors' business, Goldman said.

This 1973 model was built about halfway through the MGB's production run, but before the addition of oversized rubber bumpers, a raised ride height, and primitive emissions equipment required by United States regulations in subsequent years.

Moss Motors' 1973 MG B on Jay Leno's Garage

Moss Motors' 1973 MG B on Jay Leno's Garage

While it has a clean, stock appearance, the car has a few aftermarket parts, including a prototype Panhard rod, a supercharger for the inline-4 engine, and a 5-speed manual transmission that uses Mazda MX-5 Miata internals, Goldman said. Braking is handled by Wilwood discs up front, and drums in the rear. Switching to rear disc brakes wouldn't have a major impact, Goldman said.

Inevitably for a discussion of vintage British cars, the topic of electrical issues came up. Goldman said the real problem with MGB electrical systems today isn't flaws baked in from the factory, but years of use and abuse. This car also has a modern alternator, electronic ignition, and a high-torque starter for added reliability.

Watch the full video for more tips on upgrading classic cars, and to see Leno drive this modernized MG on the streets of Los Angeles (with the top down, naturally).