This '66 GTO may seem like an ordinary Pontiac, but what lies under its Ram Air hood is ex
Thinking outside the box. It's a common saying that carries a variety of meanings, and how literally it's taken largely depends upon the person you're speaking about. It can conjure up thoughts of an ill-conceived idea from a most eccentric individual that's obviously doomed for failure right from the start. You know the type-one that everyone can see will never pan out but plods forward, seemingly spiteful of its pending fate.
Every once in a while, however, we come across a well-thought-out example that involves proven technology, and ultimately provokes the thought, "Why didn't I think of that?" Mark McConville of Birmingham, Alabama, is one of those individuals who thought outside the box and is enjoying his '66 GTO in a completely new manner.
The way Mark's story begins isn't much different than that of other Pontiac hobbyists. "My brother, Jon, owned a '67 LeMans convertible when I was younger, and that car left quite an impression on me," states the 51-year-old owner of a transportation company. "I just loved the look of its stacked headlights and classic body lines. I knew I'd own one someday."
In 1986, he started an airport transportation service that ran between Birmingham and Atlanta, and in 2001, he branched out and began building houses. "I managed to save some money and decided that it was time to buy the musclecar of my dreams. I began looking around at mid-'60s GTOs to get a feel for the market. I heavily researched them to learn as much as I could; in 2004, I purchased a '66 GTO from an Internet website."
A previous owner had performed a body-off restoration, and though the GTO wasn't completely original, Mark felt its tasteful modifications were exactly what he wanted. "It was originally Barrier Blue but had been repainted Montero Red. The black interior was freshly restored, and a 455 resided where its original 389 once did. It had a four-speed transmission and a Safe-T-Track differential with 3.55 gears out back. It was in Portland, Oregon, so I couldn't see it in person, but it looked great in the pictures and seemed like the perfect vehicle for me."
A conventional fuel system serves no purpose after converting to CNG, so Mark removed the
Mark made the purchase and when the GTO arrived in Birmingham, he recalls the day: "I bought it sight-unseen since it was so far way and immediately thought I'd been taken. It ran great and it sounded even better, but I was really disappointed in its appearance. It had sat under a tree and was covered in sap; I thought the paint was ruined. I took it to a local detailer and it cleaned up very nicely. The body was very straight and the paint looked great. I was very happy with the purchase after that."
The motivational force behind Mark's satisfaction was a 469ci fitted with a plethora of goodies from Nunzi's Automotive in Brooklyn, New York. The XY-code '73 455 block was punched 0.060-inch to 4.21, and the journals of its 4.21-inch-stroke, nodular-iron crankshaft had been undersized 0.020 inch and polished. Four-bolt main caps from Nunzi's were added just before the main saddle was align-bored.
Inside the 469 was a set of forged-aluminum pistons with moly rings riding on fully prepared cast-iron Pontiac connecting rods. The pistons were dished enough to create a compression ratio of 10:1 when combined with a pair of No. 64 cylinder heads from a '70 455. The castings were ported and polished by Nunzi's, and fitted with stainless-steel 2.11/1.77-inch intake and exhaust valves, and heavy-duty valvesprings.
At the heart of the valvetrain was a Nunzi's No. 2042 camshaft featuring 232/243 degrees of 0.050-inch duration and 0.460/0.470-inch lift with stock 1.5:1 stamped-steel rocker arms. A Super-Duty oil pump dispensed lubricant from a Nunzi's oil pan and pressurized the hydraulic Rhoads lifters, which were used to bleed off duration at low speed, improving overall driveability.