1964 Pontiac Tempest Preferred

"The Tempest is unique and has a better-looking trim package than the GTO."

He didn't just say that, did he? Mike Holleman didn't just say he likes his Tempest better than a GTO. Blasphemy, right? No A-body could possibly eclipse the styling and performance of the legendary Goat? Well, perhaps this one can.

Mike's '64 Tempest convertible features a 421 Tri-Power engine, an overdrive trans, and a posi rear. To improve handling there are thick stabilizer bars front and rear, and stiff springs and AIS shocks at the four corners. Steamroller tires stick the machine to the pavement, and four-wheel discs stop the Pontiac in a hurry.

Why did this Morehead City, North Carolina, resident build this Tempest? "I retired from running my own business in 1998," Mike says. "Since I had given up following my passion for musclecars earlier in life to raise a family and build a business, I was anxious to jump back in with both feet. Though this Pontiac was originally bought and restored for my son to drive to high school, after he used it for a year I decided it was just too nice to be underpowered, so I hunted down a 421 for it. The conversion to a musclecar was completed in 2004 and I've driven it weekly since. It's been a Long Hauler for the last two years on the Hot Rod Power Tour as well."

Spending all that time behind the wheel and with competition from his Chevy friends who accompany him on the tour, Mike wanted to ensure his Tempest could do everything well and remain reliable.

Beginning with the chassis, he installed Hotchkis coil springs to increase the rate and lower the ride height and center of gravity. Edelbrock AIS shocks front and rear soak up road irregularities and Polygraphite bushings remove the deflection of the stock soft rubber pieces. A 1.25-inch Addco stabilizer bar works in conjunction with a 1-inch rear bar to reduce body roll in the turns. Rear lower control arms from Global West feature spherical bearings at the forward mounting points and Del-A-Lum bushings rearward to tighten up the rear suspension. Steering response has been greatly improved with a 12.7:1 ratio box that replaces the stocker.

Installing 11-inch discs all around with a Master Power kit up front and a Baer kit out back ensures short stops. Getting it all to the pavement are Foose Nitrous Thrust wheels measuring 17x8 front (4.5-inch backspacing) and 17x10 rear (5.5-inch backspacing) wrapped in Bridgestone 245/40ZR17 and 285/40ZR17 Potenza tires, respectively. Mike says the front tires never rub but the backs did at the wheelwell lip when the Pontiac was loaded and the driving got serious. Trimming the area helped but didn't cure the problem, so he ended up narrowing the rear 0.75 inch on each side. So if you're in the market for this size wheel/tire combo in the rear, 6-inch backspacing will probably work much better.

It's starting to appear that this little Tempest ragtop can show its unadorned taillights to many a GTO in the turns and in braking, but the drivetrain can make or break the combo. Mike sought the advice of Butler Performance to create a combination and provide the parts for his '65 421 engine. He then had Perform-ance Automotive Machine (Morehead City) port the heads and build the powerplant.

The 421 four-bolt main block has been punched to 434 cubes; its stock crank was cut 0.010/0.010 and refurbished and fitted with Scat H-beam forged steel rods swinging Ross forged dished pistons. A Milodon 7-quart pan and Melling high-volume pump deliver the crude to the Clevite bearings and other points of interest.

Sealed Power rings help contain the 9.5:1 compression, which was created by the chamber volume in the No. 77 heads combined with cylinder volume (with the dished pistons) and head gasket volume. Ferrea stainless steel 1.92/1.66 valves were installed in the ported and polished heads, along with hardened valve seats for street driving on unleaded 93-octane pump gas.

A Comp Cams XR276 hydraulic roller controls the movement of the valves via 5/16-inch pushrods, Isky guideplates, and 1.52 ratio Comp roller rockers and valvesprings. Duration is 224/230 degrees at 0.050 and lift is 0.502/0.510. Lobe separation angle checks in at 110 degrees.