General Motors Co is counting on muscled up, more refined versions of its lucrative Chevrolet Silverado and GMC Sierra full-size pickup trucks to show investors and car buyers the No. 1 U.S. automaker is back on the right track.

The 2014 trucks are the most critical launch for the Detroit company since its bankruptcy and $50 billion U.S. taxpayer-funded bailout in 2009. The trucks are also a linchpin in GM's perpetual battle with No. 2 U.S. carmaker Ford Motor Co , whose F-150 truck is the industry's top-selling vehicle.

GM will show off the new full-size pickups in Pontiac, Michigan, on Thursday and executives are touting the benefits of the vehicles, which will initially be offered in the most popular four-door, "crew cab" version in the second quarter next year.

"We have made significant upgrades in the key areas of the new Silverado, and improved almost every detail of the truck," Jeff Luke, executive chief engineer for full-size and midsize trucks, said in a statement. "Both Chevrolet loyalists and competitive shoppers are going to find a lot to love."

GM better hope so. Analysts estimated the company has invested $3 billion to $4 billion on developing the new trucks and related new engines, as well as for revamping the plants where the vehicles are built.

The current versions of the big trucks and related SUVs generate profits of $12,000 or more per vehicle and account for about 60 percent of GM's global profit, analysts said. Citi has estimated the new models could bring the automaker more than $1 billion in additional operating earnings in 2013 and 2014.

That would be welcome news as the last major redesign of the trucks was in 2006, and delays caused by the bankruptcy in 2009 has put GM at a competitive disadvantage in a segment that accounts for about 11 percent of the market, analysts said.

GM noted that the average age of big pickups on U.S. roads is more than 10-1/2 years, and the need to replace those aging vehicles means there is plenty of room for sales growth.

GM's U.S. dealers are chomping at the bit for the new trucks, saying the interior design is a big step forward from the current models. They say the new design will make the automaker more of a player, especially at the high end of the market, where prices approach $60,000 and margins are high.

"They're not looking to compete; they're looking to win," Jason Brickl, chief executive of Ballweg Chevrolet in Wisconsin, said of GM.

"Us having a class-leading truck is critically important to the success of Chevrolet," added Brickl, whose two dealerships in the Madison area get about a quarter of their sales from the Silverado.

GM's 2014 trucks will be new "from hood to hitch," including a trio of new V6 and V8 engines meant to improve power, torque and efficiency. GM also touted a quieter, more comfortable cab; improved steering, suspension and brakes; and the use of more high-strength steel. New safety features will include forward collision alert, lane departure warning, and front and rear parking assist.

The company said horsepower, torque and EPA fuel economy estimates won't be available until early next year. GM also did not announce pricing for the new trucks.

The current Silverado has a starting price of about $24,000, rising to almost $44,000, and the most expensive Sierra's price tag is around $57,000. Ford's F-150 starts under $24,000 and runs to almost $54,000.

GM's big trucks and SUVs -- Chevy Tahoe and Suburban, GMC Yukon and Cadillac Escalade -- remain top draws at dealerships as their combined U.S. sales rose 11 percent last year to more than 799,000 vehicles.

GM's pickup truck sales fell in November and it blamed aggressive discounting by rivals Ford, Chrysler and Nissan<7201.T>. GM has added new incentives on the trucks for December and executives indicated they will cut production to reduce supplies.

In a positive sign for the truck market, however, Citi analyst Itay Michaeli expects U.S. demand for full-size trucks to meaningfully outperform the overall industry in the next 12 to 18 months as consumers move to replacing aging vehicles.

Industry research firm LMC Automotive expects total U.S. sales this year of full-size pickup trucks to rise 8.4 percent to more than 1.62 million vehicles and hit more than 1.8 million in 2019. LMC sees GM's combined pickup sales topping Ford's next year and holding that lead through 2019.

Officials at Ford, which last redesigned its F-150 in 2008, said the company is happy with F-150's lead over Silverado.

"We're very pleased with the performance of our pickup truck over the years," Ford U.S. sales analyst Erich Merkle said. "It's been the best-selling pickup in America for 35 years straight."

The next major redesign of the F-150 will be in 2014, according to a person familiar with the automaker's plans. One area of focus will be fuel efficiency through lightweighting, including extensive use of aluminum, said the person, who asked not to be identified discussing Ford strategy.

Ford also will push to continue its dominance in the lucrative high end of the market, said Mike Jackson, director of North American vehicle forecasts at IHS Automotive. Over the past decade, Ford "has had a unique opportunity to mint money" in the premium pickup space.

Meanwhile, GM will stick with its strategy of offering both full-size and mid-sized pickups as a way to satisfy more consumers. A redesigned Chevy Colorado is expected in 2014, while both Ford and Chrysler discontinued their midsized trucks.

"If GM's two-truck strategy is successful, Ford will probably be forced to reconsider its exit from the compact pickup truck segment," Polk analyst Tom Libby said.

(Additional Reporting By Paul Lienert in Detroit; Editing by David Gregorio)