Yep, that's a fourth-generation...        read full caption Yep, that's a fourth-generation Corvette independent rear suspension under there. John says the goal for him and his crew at DF Metalworks was "to try to keep it looking stock"; we think they succeeded. The Cadillac's rear framerails did not even require cutting or radical alteration.

Small brackets (arrow) were...        read full caption Small brackets (arrow) were fabricated and welded on the frame at the rear of each kickup to mount the third member crossbeam for the IRS.

Look closely above the pumpkin...        read full caption Look closely above the pumpkin and you'll see the bracket that was fabricated to support the third member housing. The bracket hangs off an existing crossmember on the frame.

The last IRS parts requiring...        read full caption The last IRS parts requiring attention were the four-link bars. Short outriders were built off the frame to support the four-bar brackets...

...the outriders were tied...        read full caption ...the outriders were tied back into the frame's body mount arms for additional strength. John fabricated adjustable bars to replace the stock Vette pieces.

Mounting the Vette front suspension...        read full caption Mounting the Vette front suspension took a bit more work. The original frame was sliced off near the firewall, and straight framerails fabricated using 3x5-inch square tubing. This allowed the installation of the Corvette crossmember and suspension assembly...

...Note how the original framehorns...        read full caption ...Note how the original framehorns were welded to the new 'rails so the bumper and sheetmetal could be bolted on as intended. The original radiator support tied into the Cadillac front crossmember, so it had to be modified to mount on the new frame section.

At first glance, Mark Carter's '59 Cadillac Series 62 convertible looks like a nice, basic, unassuming restoration. Well, maybe not so unassuming; it is a '59 Cadillac, after all--a car that epitomizes '50s flamboyance with fins taller than some NBA stars and more chrome than a fleet of Toyotas. Like any '59, it has all the subtlety of a call girl in church. At least it's not pink.

The point we're trying to get at is that, beyond all the usual Cadillac glitz, there's more to Mark's ragtop than initially meets the eye. As much visual impact as the bright red exterior has, this Caddy is yet another example of your mother knowing what she was talking about: It's what's on the inside that counts.

More accurately, it's what's on the underside that counts on this cruiser. That's where you'll find the independent front and rear suspensions from a fourth-generation Corvette. Yeah, you heard right--full Vette suspension. There's also 502 inches of big-block Chevy under there, along with a few other assorted tricks that make this resto rod worth a closer look.

PLAN? WHAT PLAN?We'd love to say the drop-top Cad is the result of Mark's devilish master plan to have the most garish sleeper in Southern California, but the truth is it all came about somewhat by chance. Like so many other red-blooded car enthusiasts, Mark was always drawn to the '59 Cadillac's iconic design. Not only that, he had the means to buy a clean, restored example a while back. After spending some time in the driver seat, however, he discovered he didn't love the somewhat antiquated road manners, particularly the poor braking and vague handling qualities. The driving experience was less than reassuring.

Seeking help, Mark brought the red ragtop to John West at Dan Fink Metalworks. "He didn't feel safe driving the car," John tells us. "He asked me to rebuild the front suspension and put disc brakes on it. I said, 'Why not go with new technology?'"

Considering John's background building race cars, Mark paid attention. John reasoned that rebuilding the suspension and installing discs would easily cost a few thousand dollars, and Mark could buy used Corvette suspensions for less money. Granted, installation and fabrication costs would quickly eclipse any initial savings, but the end result would be a car with vastly improved handling and braking; a '50s cruiser with the contemporary road manners Mark was really looking for.

Like any good project, things kind of snowballed from there. Mark and John decided the big-block Chevy--with 450 hp and 550 lb-ft of torque right out of the crate--was not only a more powerful option than the Cad's original 390, but also more practical in terms of maintenance and parts availability. The big Rat mill was eventually tied to a Turbo 400 transmission and a custom two-piece driveshaft and center bearing from PowerTrain Industries.

MAKING IT FIT
The Corvette suspensions were chosen not only for their reputation, but also because their widths worked well with the not-so-slim Cadillac. Mounting the front and rear assemblies to the car's original frame was far from a simple bolt-on weekend affair, but it was a fairly straightforward project for the experienced crew at DF Metalworks.

Thanks to generous kickups for the original suspension, the rear framerails did not need to be reworked to fit the Vette IRS. John and his crew welded tabs to the frame to mount the third member crossbeam, and fabricated a custom bracket to hang the pinion off an original crossmember. Short outriders were built further forward on the frame for mounting the four bars.

Installing the front suspension required considerably more frame surgery. In order to eliminate the coil-spring pockets, the original framerails were cut off near the firewall and new, straight rails built from 3x5-inch square tubing. The Corvette front crossmember was then welded to the new frame section. The original radiator support had to be modified to work with the new setup, and the front few inches of the original framerails welded back on to provide proper bumper mounts.

With the Corvette front crossmember in place, installing the 502/TH400 combo was merely a matter of fabricating some relatively simple engine and transmission mounts. A double-crossflow aluminum radiator from Mattson's was employed for cooling the big mill, and a bit of custom fabrication was done to tidy up the front of the engine compartment and core support area.John selected coilover shocks from QA1 Motorsports both fore and aft, with 600lb springs in front and 500lb versions out back. A 9-inch dual-diaphragm brake booster and Corvette-spec master cylinder from Classic Performance Products were added to activate the four-wheel Vette discs. To maintain stock appearances, John had Wheel Smith build 15x7-inch steel wheels to clear the Corvette brakes; this required dreaming up an innovative mounting system for the hubcaps, as the wheels lacked the large outer lip of the original Cadillac rollers. Check out the photos to see how they made it all work.

THE RESULTS
It's safe to say that Mark's convertible no longer rides "like a Cadillac"; at least not like a typical '50s Cadillac. That's exactly how Mark wants it. Gone is the squishy, cushy, floating feel that disconnects the driver from the road. In its place is a firm, responsive ride--solid and comfortable, but not harsh. In our short time in the car, we noticed how it settled right back down after traversing bumps and railroad tracks, rather than bouncing and wallowing all over the road. There was very minimal leaning and listing around corners, as well. Likewise, the braking was very reassuring, although John tells us he's still looking to improve high-speed braking with aftermarket rotors or calipers. This is still a heavy car, after all, even after shedding an estimated 300 lbs during its transformation.

There's still a bit more fine-tuning to do. Mark would like the car to sit an inch or so lower, so shorter front springs are on the way; the rear coilovers will simply be adjusted. A Vintage Air system is also slated for installation, for those days when it's a little too warm or cold to put the top down. With that, the Cadillac should be everything Mark ever dreamed of--a car with iconic '50s styling and comfortable, modern road manners. And you thought it was just another resto.

This view from the engine...        read full caption This view from the engine compartment shows the upper control arm mount (which is part of the crossmember) and the custom upper mount for the coilover shock (remember, these Vette suspensions still employed transverse leaf springs). Also note the simple engine mount, as well as the more-than-ample clearance for exhaust headers.	The DF Metalworks crew put...        read full caption The DF Metalworks crew put its sheetmetal skills to use fabricating a cover for the aluminum radiator overflow catch can and power steering reservoirs on the driver side, and a battery box on the passenger side...	...The two compartments form...        read full caption ...The two compartments form a channel that funnels air to the radiator, which is a double-crossflow aluminum unit from Mattson's.
If not for the modern-style...        read full caption If not for the modern-style dipstick, valve covers, and a few other accessories, the GM Performance Parts big-block would look almost factory. It certainly has plenty of room in the Cadillac engine compartment. The aluminum fan guard above the radiator is a nice finishing touch.	The wide whitewalls, steel...        read full caption The wide whitewalls, steel wheels, and stock hubcaps really help maintain the car's resto/sleeper image. Wheel Smith built the 15x7-inch rims to clear the big Vette rotors and calipers, but the new rims lacked the large lip necessary to grip the hubcaps...	...So John devised a clever...        read full caption ...So John devised a clever alternate mounting solution. A flathead allen screw secures the cap to a threaded steel rod, which is bolted to a truck-style hub cover mounted behind the wheel. The hubcap's original center emblem--now secured using hook-and-loop material--covers the screw head. The wide whitewalls are P235/75R15 radials, and also came from Wheel Smith.