Jim Smart
April 16, 2012

Last month, we showed you how to get into the sophisticated, high-performance Heidts Pro-G front suspension with help from our friends at Stang-Aholics. This month, we're going to show you how to install the Heidts Pro-G Independent Rear Suspension (IRS) for '65-'70 Mustangs. When you build in Pro-G suspension technology, you've effectively changed your classic Mustang forever. There's really no turning back, because once you experience the difference, you probably won't want to go back to a conventional Mustang suspension again.

This isn't a sales pitch, but a fact, because this is radically different suspension technology for these dusty old classics. Old Mustangs come alive with Pro-G. Installing Pro-G fore and aft changes everything and here's why. The Heidts engineering team has taken independent rear suspension and raised the benchmark with a system capable of withstanding up to 600 horsepower. There has never been another suspension system like it for Mustangs because it features a fully welded and boxed frame designed to fit your classic Mustang platform. It can be bolted or welded in, though we suggest both. Here's what you get for your money:

  • Bulletproof 9-inch aluminum housing
  • Iron third member in a variety of gear ratios including 3.00:1, 3.25:1, 3.50:1, 3.90:1, and 4.11:1
  • Heavy-duty CV joints and halfshafts
  • Strong tubular upper and lower control arms
  • Steel outer uprights
  • Fully welded and boxed upper crossmember
  • Heavy-duty frame mounting brackets
  • Front pinion support
  • Forward struts (used with subframe connectors)
  • 10.5-inch Wilwood brakes
  • Black Wilwood calipers
  • Billet single-adjustable coilover shocks with chrome springs
  • Choice of gear ratios
  • Choice of spring rates
  • Optional parking brake kit
  • Optional parking brake cable kit

What's This Going to Cost Me?

This kind of technology doesn't come cheap. Expect to spend a minimum of $8,000 plus any taxes and shipping for the Pro-G Independent Rear Suspension system. Parking brake calipers and cables will cost more. If you want high-performance slotted disc brakes, the price goes upwards of $8,300. The nice part about Pro-G is the convenience. You can bolt this system on first, then weld it in place later once you're confident it's a keeper. After a testdrive with a good four-wheel alignment, we're confident you're going to like the new Pro-G system.

What's In It For Me?

Heidts technology lowers the ride height for vastly improved center of gravity--a real road hugger you're going to want to drive daily. That old-school Falcon-esque “clunk” from road irregularities like chuck holes and dips vanishes, is replaced by a buttery smooth event void of road shock. The ride becomes smoother and the handling crisp. You'll hop into your buddy's concours-restored original Mustang and want to file for federal disaster relief because this upgrade is that good.

The Heidts Pro-G Independent Rear Suspension isn't a simple system you can install in a weekend with basic handtools and jackstands. You must have some fabrication skills or know a good fab shop with a known good reputation, because there's a lot of cutting and welding going on here. If you don't have access to a welder or know how to weld, you can bolt this system in. Good advice is to have it welded once it's bolted in and properly aligned for best results.

There's never been another suspension system like it for Mustangs because it features a fully welded and boxed frame designed to fit your classic Mustang platform. It can be bolted or welded in, though we suggest both.

Photo Gallery

View Photo Gallery