A Norfolk shipbuilding firm whose president and other key officers were convicted of conspiring to bribe U.S. Navy inspectors three years ago has given $2,500 to the Virginia gubernatorial campaign of Republican candidate John N. Dalton.

The donation disclosed yesterday in a list of Dalton's campaign contributions and expenditures came from the Norfolk Shipbuilding and Drydock Co., the city's largest private employer.

The check was signed by company president John L. Roper III, 49, who served nearly for months in federal prison for his role in the conspiracy. Roper and his brother, George W. Roper II, 48, a company vice president, each were sentenced to three years in prison and ordered to pay a $10,000 fine. All but four months of the prison terms were suspended.

The shipyard contribution to the Dalton campaign was first identified as a personal donation by Roper. Richard Lobb, Dalton's press secretary, later said it was a donation of corporate funds, which is permitted under Virginia election laws.

When it was thought to be Roper's personal contribution, however, Lobb said the Dalton campaign had no intention of returning it because of the Roper convictions.

The Roper brothers and five other lower ranking officials in the company were convicted of conspiring to bribe ship surveyors to make generous estimates of the cost of repairing Navy vessels. Ship repair is the main business of the company.

Fifteen government employees, chiefly gratuities from Norfolk Shipbuilding and other shipyards in connection with the repair scandal.

"John Roper is a fine and upstanding citizen of Norfolk and leads a major employer in the state," Lobb said. "If he made a mistake, he has paid his debt to society. We have no intention of slapping him in the face by sending back his check."

Faced with a similar situation late in his party primary campaign last spring, Dalton's Democratic opponent, former Lt. Gov. Henry E. Howell, took the opposite course.

Howell, desperate for funds two weeks before the June 14 primary election, was promised up to $75,000 in donations by southwest Virginia business promoter Robert E. Bales of Glade Spring.

However, when he learned that Bales was on five years probation for income tax evasion and making false statements on loan applications to federally insured banks, Howell rejected the promised aid, saying:

"I have always believed that all candidates running for public office should be above reproach . . . Not desiring to embarrass Mr. Bales or his family in any way, the Howell campaign will not accept his offer of a contribution."

Lobb rejected any comparison of the Bales and Roper cases. "There is a world of differences between the Roper family" and Bales, he said.

The Roper family is among the best known in Norfolk's business and social world. Family members have long supported Republican candidates.

Bales is well known in his part of the state for promising ambitious real estate developments. In addition to his federal convictions, he was once convicted in a Rockbridge County Circuit Court of writing a check against insufficient funds.

The Howell campaign has received a $6,500 donation from a Northern Virginia entrepreneur, john D. Schrott Jr., who became enmeshed in lawsuits over a wine contract fraud in 1974. However, Schrott was not accused of any criminal violations.

Schrott was named by the Securities and Exchange Commission staff as a participant in the wine sales scheme headed by Robert Dale Johnson that cost investors millions of dollars when it collapsed. Without admitting any wrongdoing, Schrott agreed to sing an SEC order in which he promised not to sell unregistered securities in the future.

Following the signing of the SEC agreement, he settled several lawsuits filed against him by banks and investors who alleged that Schrott attracted them to the wine investment plan.