CARS : PONTIAC SHOW : Classic Cruisers : * Owners pack up pride and nostalgia in their prized, spick-and-span automobiles for three days of activities, competition and fun.

Ventura is going to be invaded this Friday, Saturday and Sunday. By Pontiacs.

Coming in all shapes and sizes--some 1950s models seem only slightly shorter than a Navy cruiser--the event might be mistaken for a scene out of “American Graffiti,” especially Friday evening when everyone is scheduled to assemble their steel Indians at Hudson’s Grill on Telephone Road to recreate “cruise night.”

It’s not a scene from a movie, but part of the 7th Annual Western Region Convention of the Pontiac/Oakland Car Club being held this year at Harbortown Marina Resort in Ventura. Club members said events such as cruise night will be a great time for nostalgia, complete with hamburgers, tire-kicking and plenty of people “talking Pontiac.”

But if you’re not a member and don’t own the right car, don’t despair. During the convention’s swap meet and car display, which will feature a range of cars, from a 1933 convertible coupe to a 1990 TransAm, the public is invited--for free.

“The theme of the club is the preservation of the car,” said member Dick Hoyt, 50 of Canoga Park. “This isn’t a hot rod club. Most of the guys are trying to put them back to their original specs.”

The “them” Hoyt refers to are not only Pontiacs, but its sister car, the discontinued Oakland, both of which can trace their bloodlines to the 1890s and the Pontiac Buggy Co. of Pontiac, Mich. Later known as the Oakland Motor Car Co., by 1909 it had become part of General Motors. In 1926, the Pontiac re-emerged as a separate car with such success that its Oakland parent was dropped from the GM line six years later.

The car club has a much shorter genealogy. Begun in 1972 by a couple of Escondido, Calif., Pontiac owners who felt a club might be an easier way to scrounge for hard-to-find parts, the national organization has about 9,500 members and the Southern California chapter slightly more than 250.

Quoting statistics on how many hard-core Pontiac club members there are is one thing, but finding out why people choose this particular make over, say, a Plymouth, is a little harder to explain. For many members, it turns out a Pontiac was their first car. Or their dad’s.

“My father worked for Pontiac when I was in high school,” said Dan Santoro, 43 of Placentia. “I bought a 1959 Bonneville right after graduation, but sold it when I went into the Air Force.”

Years later, lamenting that it was probably the best car he had ever owned, his future wife suggested he get another one. Today, he owns two restored 1959 Pontiac Bonnevilles and a 1964 Pontiac Grand Prix.

Rich Plastino, 50, of Corona del Mar, learned to drive in one.

“I had a 1940 Pontiac when I was a teen-ager and grew up on Hot Rod magazine,” he said, “so when I decided to hobby, it was only natural my wife, Jan, and I joined a car club.”

The Plastinos own three Pontiacs, including a 1957 Safari station wagon and a 1964 Catalina, but it is their 1933 coupe that they are the most proud of. “It’s got panache,” he said.

Don Finn, 57, of La Habra feels the same way about his 1959 Bonneville two-door sport coupe.

“I’ve always liked the older cars,” he said, explaining that the Bonneville trunk was so large that after removing the spare tire, he and his wife used to sleep in it when the couple went camping. Twenty-nine years later, his wife, Barbara, now 53, laughed and said: “I didn’t know if I fell in love with him or that car. All that chrome!”

But Finn sold the car shortly afterward, and said he regretted it ever since. Five years ago, after an extensive search, he purchased another.

“It’s a far cry from when I first saw it,” he said. “It followed me home, smoke coming out of it and dented. It barely ran.” Now equipped with a new engine, the rust removed, the upholstery redone, a glistening paint job smoothing over three decades of wear, it is, in the eyes of its owner, a thing of beauty.

Then there are the Pontiac owners, like Hoyt, who are only interested in one particular year.

Hoyt owns three 1957 limited-production fuel-injected Bonneville convertibles, one of them being the only black one ever made. Of the original 630 cars produced, he estimated 50 are left today. Since he began collecting 30 years ago, Hoyt has had four Bonneville convertibles, a standard Star Chief convertible and a Safari wagon--all 1957s.

Hard-pressed to explain why he prefers that year, Hoyt said that to him, “ ’57 Pontiacs just have a lot of elegance and beauty.”

The city of Ventura was chosen for this year’s convention because, “it’s a beautiful location,” said club members, “and it’s not overly hot this time of year.” The latter is an important point, they said, because some of the older cars as well as a few of the 1960s “muscle cars,” like the GTO model, tend to overheat. Past host cities have included Prescott, Ariz.; Santa Clara, Calif.; and Las Vegas.

The three-day event is scheduled to be divided into a number of segments including Cruise Night, which Hoyt said is actually “park night” at Hudson’s Grill; the swap meet, where members can sell their oversupply of bumpers, shock absorbers and widgets to those who just happen to be searching for that exact part; and the Car Corral, where members can bring Pontiacs that they are trying to sell.

While the swap meet is open to the public, the biggest draw, said club officials, is the Saturday Car Show from 10 a.m. to 4 p.m., where more than 150 vehicles will be on display competing in one of 32 different classes, including Best Convertible, Best Station Wagon, Best 1930s Car, Best 1940s Car and the highest award, Best of Show.

Despite the heavy male-orientation of the hobby, club members insist their wives, often silent partners in helping find parts as well as being chief psychologists in soothing a furrowed brow when “the blasted part just won’t fit,” have not been forgotten. At 9 a.m. on Saturday, they have their own “Ladies Brunch.”

“I love the social aspect of the club,” said Barbara Finn. “We all have the same interests and while I don’t know as much about cars as Don does, it’s a fun group.

“I’m a Pontiac widow, but I don’t mind,” she said gamely. “At least I don’t have to put up with football games.”

* THE DETAILS : To join in the fun, or just watch the cars go by, here are the convention events that are open to the public:

* On Friday night, everyone participating in the ‘Cruise to Hudson’s’ will meet in front of the Harbortown Marina Resort about 7:30 p.m. and at 8 p.m. will head to Hudson’s Grill on Telephone Avenue.

* The swap meet and “Car Corral,” where members will be selling their Pontiacs, begin at 7:30 a.m. on Saturday across the street from the hotel and is expected to last until about 3 p.m.

* At 9 a.m. Saturday there will be a new car show of 1990 Pontiacs.

* Beginning at 11 a.m. on Saturday will be the main event for the public, the car show with about 150 cars on display, ranging from 1933 to the present.

* At 2 p.m. will be the technical seminar inside the hotel at the Harbor View Room.