1970— Pro Stock debut 1972 — Weight breaks and

S
ince the Winternationals became the NHRA
season opener in 1961, the event traditionally has been the showcase for impressive
technological advancements and memorable pivotal happenings, occurrences that set the tone
for the rest of the season. The trend is espe-
cially notable in the Pro Stock class, which got
its start at the fabled Pomona Raceway event 35
years ago.
1970 — Pro Stock debut
The first NHRA national event to host a Pro Stock
competition was the 1970 Winternationals, which stands
out for how radically different the original breed of factory
hot rods was from the technologically advanced marvels
that compete today. The first Pro Stockers were made from
stock-framed, factory-produced vehicles (no tube chassis)
and ran at a weight factor of 7.0 pounds per cubic inch
compared with today’s factor of 4.7 pounds per cubic inch,
including driver. That put the 427 Chevy and Ford entries
and the 426-cid Mopar vehicles at just under 3,000 pounds.
Current Pro Stockers have a 500-cid engine and weigh
2,350 pounds, including driver.
Despite such handicaps, the first Pro Stockers
produced nine-second clockings, led by Bill Jenkins’ low
e.t. of the meet 9.98. By the end of the inaugural season,
Don Nicholson’s Ford Maverick had lowered the national
record to 9.81.
The winner of NHRA’s first Pro Stock national event title was Bill “Grumpy” Jenkins, at the 1970 Winternationals. His
Camaro compares tamely to today’s nine-second Super Gas cars and, except for its fiberglass body components and
hood scoop, it actually compares more closely to a current Stock entry. The car’s stock chassis was modified only
by framerail connectors, stock A-frame front suspension, and stock-type leaf springs equipped with traction bars.
Not only did Jenkins’ small-block Vega win the first NHRA national event
in which weight breaks were implemented, but it was also the first Pro
Stocker to use tube-frame chassis components, installed from the firewall
back. The front frame and front suspension, though braced with extra tubing, were still essentially stock. Jenkins did not introduce the first
McPherson strut front suspension until the 1974 Gatornationals.
1972 — Weight breaks and tube chassis
After the first two seasons of Pro Stock competition in 1970 and 1971, there was no doubt that
the factory hot rod category was a big hit with the fans. But NHRA officials were concerned that
the overwhelming success of the Dodge and Plymouth entries, which had won 12 of the 15 races
held during those two years, could hurt the class.
Said then-NHRA Competition Director Steve Gibbs, “At the end of 1971, there was no doubt that
Chrysler had achieved total domination of Pro Stock, and the class was bound to suffer. We decided
to implement weight breaks to encourage some other makes to get back into the program.”
NHRA accordingly switched from the original 7.0 factor for all types of cars to 6.75 for
small-block entries and 7.25 for cars with big-blocks.
Only one small-block entry showed up at the 1972 season opener in Pomona: Jenkins’ 331-cid
Chevrolet Vega. Said Jenkins, “I was going to build the Vega whether NHRA went with a weightbreak format or not. I could’ve used it for match races.”
Tuning problems held Jenkins to a qualifying best of 9.90, which put him in the 17th position
of the 32-car field and forced him to race Stu McDade, driver of Billy Stepp’s Dodge Challenger
that had qualified No. 1 with a 9.59. But Jenkins made some pivotal suspension changes prior to
the first round and managed to quicken his pace to a 9.63 to defeat McDade’s 9.75. Jenkins went
on to defeat four more Hemis to score a crowdpleasing victory, the first of six wins in eight races
that earned him the 1972 NHRA Pro Stock championship.
Ford later got into the act with small-block Pintos campaigned by the likes of Bob Glidden,
Gapp & Roush, and Nicholson, who won the NHRA Pro Stock title in 1973.
1973 — Lenco clutchless four-speed transmission
The 1973 Winternationals was run over three weekends because of multiple rainouts, and by the time the race
was completed, the landscape of Pro Stock had changed significantly with the introduction of the Lenco clutchless
four-speed transmission. Prior to this race, manually shifted units had been used almost exclusively. Fans were
thrilled to witness the skills of true four-speed wizards such as Ronnie Sox and Nicholson, but the high rate of drivetrain breakage was elevating maintenance costs at an alarming rate.
The Lenco transmission, with its planetary gears, permitted clutchless shifting that was not only easier on the
driveshaft and rear-end assembly but made every driver in the class just as consistent as Sox.
During the first weekend of the Winternationals, Lenco-equipped cars took three of the top four positions, led by
Nicholson’s 9.41 with his Ford Pinto; Melvin Yow, in Stepp’s Dodge, and Jack Roush’s Pinto took the No. 3 and 4
spots, respectively. Only No. 2 qualifier Jenkins, who ran a 9.42 with his ’72 Vega, was among the elite runners
with a manually shifted four-speed.
More teams jumped on the Lenco bandwagon during the second weekend of qualifying; Don Carlton lead the way
in Ted Spehar’s Motown Missile Dodge with a sensational 9.22, at the time the quickest run ever recorded by an
NHRA-legal Pro Stocker.
By the time eliminations were finally completed, virtually every Pro Stock team had switched to a planetary-type
transmission or was making plans to do so.
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64
✦ National
DRAGSTER
Though Don Nicholson was known as one of the
nation’s more skilled drivers with a manually shifted
four-speed transmission, he had no trouble making
the transition to the Lenco clutchless four-speed at the
1973 Winternationals, where he won the event and set
new national records of 9.38 seconds and 148.76 mph.
1979 — Glidden’s Plymouth Arrow
from page 64
Bob Glidden had enjoyed the best season of his career thus far — seven wins
in nine national events with his Ford Fairmont — in 1978, so it was shocking that
he came to the 1979 Winternationals with a Plymouth Arrow powered by a smallblock Mopar engine. Most trackside observers predicted it would take Glidden at
least six months to sort out the new combination, but Glidden secretly had been
working on the project during the last half of 1978 and was in midseason form in
Pomona, where he not only won the event but tied the national record with a low
e.t. of the meet 8.49 and set top speed at 159.57 mph.
Said Glidden, “We’d had a lot of success on the track with our Ford
program in 1978, but I wasn’t getting any financial support from [Ford].
Plymouth approached me during the middle of the year and offered some
money if I would switch to one of their cars.”
Glidden tested the new Arrow one week prior to the Winternationals. “It
was the first time the car went down the track,” said Glidden, “but we knew
right then that the car was going to be pretty quick and fast.”
After handily winning the Winternationals, Glidden went on to win seven of
the year’s nine events for the second campaign in a row, losing his only two races
on red-light starts in the final of each event. “To us,” said Glidden, “the Arrow
was even more successful than my undefeated Fairmont, especially when you
consider that we had to start from scratch with an entirely new combination.”
Glidden would have continued his program with Plymouth, but Chrysler
suffered a financial crisis in 1979 and claimed bankruptcy. “Contracts like
mine were the first to go,” said Glidden. “Fortunately, we were able to go
back to Ford, and this time they came up with some financial support.”
Glidden qualified his new Plymouth Arrow No. 1 with an 8.56 he recorded in the first session.
He then turned times of 8.59, 8.50, and 8.55 during eliminations to reach the final, where he
defeated Joe Satmary’s Camaro, 8.49 to 8.71.
1982 — The 500-cid mountain motor
When weight breaks were first introduced to Pro Stock for the 1972 season, there were just two:
for cars with either small- or big-block engines. A third was later added for canted-valve wedge
engines, followed by two more for cars either over or under a wheelbase dimension of 105 inches.
By the 1981 season, weight breaks had evolved into one for every type of engine raced in Pro
Stock, 11 at the time, and the total number was doubled to 22 with the wheelbase factors. Racers
and sanctioning-body officials alike had grown weary of the disputes over weight breaks, which
were also changed at various points of the season, so the decision to return to a heads-up format
in 1982 was welcomed by all parties involved.
The weight breaks were tossed
out in spectacular fashion with the
introduction of the 500-cid
mountain motors, which would
produce a quantum leap in horseLee Shepherd, near lane, earned the distinction of producing NHRA’s
power and torque over the 330- to
first seven-second Pro Stock run with a 7.86 during Thursday’s open350-cid engines most commonly
ing qualifying session. Clutch problems slowed Shepherd to an 8.02
used through the end of 1981. With
in the final, and Frank Iaconio won the event with a 7.83. Iaconio also
a new minimum weight of 2,350
came away with a national record of 7.82, shattering the old weightpounds, including the driver, this
break standard of 8.23.
Bob Glidden, who was preparing this Ford EXP to be raced with a
new package promised great gains
small-block engine on the premise that the weight-break format
in performance, and the debut of the new format at the 1982 Winternationals more than lived up to its
would be continued in 1982, was surprised by the announcement late
advance billing with 7.8-second elapsed times and 174-mph speeds.
in 1981 that the 500-cid rules would be implemented. He showed up
Perhaps the best measuring stick regarding this rule change is that it has remained virtually
at the Winternationals with his car hastily converted to accept the
untouched for 23 years. Racers have been able to focus on this format, resulting in the 6.6-second
larger powerplant and not only managed to qualify third with a 7.89,
elapsed times and nearly 208-mph speeds that are truly amazing for a naturally aspirated engine
but he also reached the semifinals in eliminations.
running on automotive-type gasoline.
1983— Aerodynamic Pro Stockers
With the advent of the more powerful 500-cid engines in 1982 that
quickly pushed Pro Stock speeds from 165 to 180 mph, aerodynamic
factors became considerably more significant. Consequently, General
Motors had Reher-Morrison bring its Don Ness-built Camaro to the
corporation’s wind-tunnel facility in Detroit for three days of extensive
testing and evaluation. Said David Reher, “We had a big audience for
those tests. All eight of the GM aerodynamic engineers were present,
including Gary Acker, who later went to the Hendricks NASCAR team
and now has his own wind-tunnel operation in Mooresville, N.C.
“A lot of those ideas were implemented onto our car before the 1983
Winternationals. Other things evolved after that, including the flatter
spoiler that you still see these days, and extending the back of the hood
scoop all the way to the windshield to eliminate the air turbulence we had
previously experienced. Gary established just about every area of development that we still work on today, and Don was an excellent on-the-spot
fabricator for the desired modifications. We are still looking for aerodynamic gains, but it’s like our current engine development in that we’re
approaching the point of diminishing returns, and significant gains are
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harder to come by.”
✦
66 National DRAGSTER
This Reher-Morrison Camaro was subjected to an extensive three-day wind-tunnel test, the first
of its kind for a Pro Stock vehicle, at the General Motors facility in Detroit. This car showed up
at the 1983 Winternationals with a number of aerodynamic improvements that resulted from
that session, including lowered rocker panels, modified wheelwell openings, flush-mounted
windshield and windows, and other significant developments.
1985 — Funny Car-style roll cages
from page 66
The Don Ness-built cars of
Butch Leal (right) and
Iaconio showed up at the
1985 Winternationals with
what is to believed to be
the first examples of the
driver-encapsulated (or
Funny Car-style) roll cage.
It was designed to retain
the driver in the cockpit
seat and keep him or her
within the protective area
of the basic roll cage in
cases of turnovers during
high-speed incidents.
Warren Johnson
implemented a similar
configuration in his
Oldsmobile Calais that year.
The modification has been
standard equipment on all
Pro Stock vehicles for
many years.
Higher speeds required not only improved aerodynamics but
extra driver protection for a class that originally began
running at speeds of 140 mph or slower. Said chassis builder
Ness, “It became apparent to us that more needed to be done
to contain the driver within the parameters of the roll cage in
case [a car lost control] at high speeds, so we came up with an
additional framework that encapsulated the driver. The first
two such cars I built were a Pontiac Firebird for Butch Leal on
the Rod Shop team and Frank Iaconio’s Budweiser-sponsored
Ford Thunderbird. I think Warren Johnson came up with a
similar design for his Oldsmobile Calais that year.”
“The G force that a driver’s body is subjected to when a car
flips at high speed is beyond imagination,” said Ness. “We
needed that extra reinforcement located close to his body to
keep him safely harnessed to the driver’s seat and retained
within the protective framework of the already standardized
roll cage. I think this design has proven its value numerous
times over the years when we’ve seen drivers walk away from
what looked to be some pretty spectacular incidents. NHRA
and the SFI Foundation were instrumental in helping us
develop the specifications to make this modification a requirement within the NHRA rules.”
2001 — Standardized body styles
With so many Pro Stock races being decided by mere
thousandths of a second, such considerations as the length of
the front overhang of the body, which trips the win light at the
finish line, became a critical factor that favored cars with longer
dimensions in that area. In an effort to level the playing field,
NHRA began the practice of standardizing body specifications.
Said longtime Pro Stock chassis builder Jerry Haas,
“The Chevrolet Cavalier and Pontiac Grand Am were introduced [in 2001] to replace the Camaro and Firebird, which
made it a good time to implement rule changes. The
Oldsmobile Cutlass body, which had been used for several
years, had a 105-inch wheelbase, and that was selected as
the standard specification. NHRA also decided to allow a
45-inch measurement from the spindle to the nose of the
car to standardize the front ends. We were able to implement these changes while still retaining the basic shape of
each body design in order to maintain proper brand identity. I think that it is one of the selling points of Pro Stock
in that you don’t have to read a car name on the bumper in
order to tell what brand or model it is.”
2004 — Beadlock tires
With the introduction of the new Chevrolet Cavalier and Pontiac Grand Am body styles in 2001, such as
those campaigned respectively by Kurt Johnson, near lane, and Bruce Allen, NHRA decided to
standardize the wheelbase dimension at 105 inches and the spindle-to-nose front overhang at 45 inches.
The latter specification was significant because it eliminated the inherent advantage of vehicles with a
longer nose tripping the win light at the finish line.
According to Warren Johnson, “The implementation of the beadlock
wheel/tire combination for Pro Stockers in 2004 probably did as much to
provide additional safety for the class as did the Funny Car-style roll cages that
were introduced in the mid-1980s. The former method of attaching the tire and
wheel together with a bunch of sheet-metal screws had become archaic and
highly unsafe. In a tubeless configuration, all you need is to break the seal just
a little bit and you have a flat tire, which can spell disaster when you’re at
speeds at well over 205 mph at the finish line.”
Admittedly, there was a significant amount of opposition to the new regulations, which took effect at the 2004 Winternationals. Among the issues cited
was the extra reciprocating weight as a performance-inhibiting factor, increased
costs to beef up the rear-axle housing assembly,
and the testing and development procedures to
produce stronger ring-and-pinion gears with
optimum ratios.
Greg Anderson dissipated any fears of
performance setbacks when he began the
“beadlock era” by breaking his Pomona Raceway
track records of 6.733, 205.51 mph with new standards of 6.706, 206.13.
Johnson added, “In the 18 months [prior] to this
decision, we had seen a number of drivers get
upside down when their cars got out of the groove,
and all of those incidents could’ve been averted
with the beadlock tire. This turned out to be a winwin situation for all concerned.” ND
(Above) Through the 2003 season, Pro Stock cars used
sheet-metal screws to attach the wheel and tire together, a
procedure that dated back to the 10-second, 128-mph
A/Factory Experimental cars campaigned in 1964. (Left)
Beginning with the 2004 Winternationals, Pro Stockers
were required to use 16-inch beadlock wheels, which
consisted of an outer rim connected to the wheel by a large
number of fasteners to keep the tire firmly in place. Not only
did this new rule help provide better sealing capabilities for
the tubeless rear slicks, but it improved the stability of Pro
Stock vehicles, resulting in fewer aborted runs.
February 11, 2005 ✦ 69