Pro Street 1970 Pontiac GTO - Gleaming Tower Of Power

Back On The Road ... Briefly

Pleased with the results, the Bolins began to show the Pro Streeter and garner some attention in the spring of 2005. They decided to attend the Ames Performance Pontiac Nats in Norwalk and borrowed an enclosed trailer to bring the car from Maryland to Ohio. Then it happened: "I had a trailer-tire blow out and flipped the trailer with my car in it," Bill laments. "I had just left my brother Brian's work where he sells tow trucks and equipment, so I called him. He and a couple of his customers showed up in 10 minutes with two tow trucks. After flipping the trailer onto its wheels and towing it back to my brother's shop, my wife and I decided to go home, get my open trailer, and go to Norwalk with the damaged GTO anyway. I'm glad that we did as we enjoyed the whole event. We met tons of great people, and to top it off, the GTO still won 'Best Pro Street Car' in the car show." How's that for perseverance?

The Repairs

Once back home, repairing the body and paint became the main concern. "I found James 'Cotton' Hemsley of Newburg, Maryland through a friend," Bill says. "Cotton is semi-retired but was intrigued by my GTO after seeing the engine and interior. He said all the car needed was some TLC and paint to be different from most cars around."

After the body repairs were completed and five coats of PPG primer were blocked to perfection, PPG sealer was applied. Cotton then sprayed three coats of silver base followed by seven coats of orange. Next came seven coats of clear and wet-sanding with 1,200 grit on the first coat, then 2,000- to 3,000-grit paper on subsequent coats before the final polishing. It took just five weeks from start to finish, and Bill had his GTO back and looking better than ever.

Blower Stacking

Next came the installation of a system that many supercharger companies said was mechanically impossible-a double-stacked blower setup. Bill installed another BDS Stage 2 blower, an 8-71 on top of the first one, and worked out all the bugs of the blower drives, belt, and so on to make it work. He explains, "I did lots of research on my own, and I tried a setup that I thought should work, and it did. It's been on my GTO and has operated without a problem since May 2006.

"I took a blower-baseplate gasket and a two-carb adaptor gasket to General Machine in Landover, Maryland, and had them make an adaptor that would mate to the carb flange on the 6-71 and act as a baseplate for the 8-71. Once the blowers were mounted, I used a long snout, designed for a 460 Ford, on the top blower to extend the pulley beyond the normal position of the lower blower pulley. The bottom blower uses the regular Pontiac 3-inch snout and two pulleys bolted together, one to run the crank belt and the other to run the top blower's short belt. The bottom 6-71 blower runs 1:1 with the crank using 33-tooth pulleys. At top, the 8-71 blower is 8 percent underdriven using a 36-tooth pulley on it to try to even out airflow between them since the 6-71 can move 411 ci of air per revolution, and the 8-71 can move 435.

"I also had to install a 60-inch Lokar throttle cable to reach the carbs, and I extended the fuel lines. Currently, the engine is set up to run a bit rich to keep it on the safe side of detonation by using the mixture to also help keep combustion chamber temps lower."

Double Blower Realities

To be realistic, this 474 can get all the air it will ever need from the single blower; Bill knows that. With the 6-71 single blower and a mismatched previous torque converter that had a 5,500 stall, the 3,300-pound (3,500 with driver) GTO ran the quarter in 10.26 at 122 mph on motor, 8 percent underdriven, and at just 4 psi of boost, according to Bill. He recalls: "The stall speed was totally wrong for the combo, and the car was 'blowing through' the converter. As a result, the engine was bouncing off the 6,800-rpm rev-limiter chip from the 1/8-mile to the traps."

Bill is looking for 9-second timeslips with the new tighter converter, but he also admits that the second blower, while it looks killer on the street, will probably be more of detriment to that goal than a help due to the amount of horsepower it takes to drive it, amount of heat it will generate while delivering air to the blower beneath it and the engine despite the intercooler, and the fact that the single 8-71 is large enough to feed the engine anyway. He also realizes that should the second blower offer a performance benefit, the reward will probably cause a hasty evacuation of the contents of the short-block.

For those reasons, Bill is planning on yanking the 6-71 blower and heading back to the track with the single 8-71 13-percent overdriven to make some more passes with increased boost.

Conclusion

After seeing this GTO, you might say, "That's nice, but I bet it never gets driven anywhere except for a few times on the track." You would be wrong. Bill says he drives the GTO over 2,000 miles per year to cruises and events. Speaking of events, the Goat has already racked up an impressive array of trophies since its second buildup. It even won HPP's Editor's Choice award at the Ames Performance Pontiac Nats in 2006.

Though two blowers on top of each other are not the most efficient in terms of pure performance, they do get you noticed everywhere you go, and that was Bill's intent from the beginning. Given the size of the crowd that gathers each time the GTO shows up, we'd say that he achieved his goal without ever slowing down despite the trailer accident that damaged his prize Pontiac just a year ago.

Bill sums up his Pro Street Pontiac thusly: "I compare it to Pamela Anderson. Some people think she's hot, and others think she's fake. Either way, if she walks by, you're gonna look!"