Ronald Reagan, who made a show business fortune reading scripts written by others, is trying to raise a political fortune by using a fund-raising script borrowed from a conservative opponent, Rep. Philip M. Crane.

The Crane script -- actually an emotional letter appealing for campaign donations -- went out back in August 1978. The Regan version was mailed 15 months later to about 800,000 would-be contributors. It used the same format, the same issues and many of the same words Crane had used.

"It looks like the only thing they changed was where to send the check," a Crane aide said. "I guess you can't teach an old dog new tricks."

Crane's longshot bid for the GOP presidential nomination is based on the premise that he is a younger more vigorous version of Regan. Crane is 49; Reagan is 68.

Only the names and dates were changed in 10 of the first 11 paragraphs of the Reagan letter. Even the opening paragraph of the Reagan appeal is only a slightly altered version of the Crane script.

In his letter, Crane says, "I want you to be one of the first persons to know that I've decided to run for president." Reagan, the GOP frontrunner, adds only five words to that, saying, "Because of your past support I want you to be one of the first persons. . . ."

The fifth through tenth paragraphs of the Reagan letter are almost direct lifts from the Crane letter. Only one verb, for example, separates Reagan's version from Crane's in the paragraph that says: "I hope in the coming months when I visit [addressee's state] that you will have the time to meet and talk to me about my campaign for President."

The letter is an embarassment to the Reagan campaign, which is trying to portray the former California governor as a vigorous senior stateman, full of creativity and new ideas.

When told of the similarities between the two letters, press spokeswoman Nedra Carpell said, "Gee-ee-ee.And you can quote me on that."

Later, Jim Lake, Reagan's chief press secretary, retrenched. "There are certain key tricks one uses in going about direct mail fund-raising," he said. "It's not surprising to me that the wording in the two letters would be similar."

Ironically, one of those who received the Reagan letter was the author of Crane's letter, conservative direct mail expert Richard Viguerie.

"It looked awfully familiar when I read it," he said. "So I went to my files and found it looked exactly like it.

"It is one of the best letters I ever wrote. It raised a lot of money for Phil Crane."

The Crane letter was not copyrighted and Viguerie doesn't plan any legal action. But he said he has never encountered such a blatant example of plagiarism in all his years of direct mail fund-raising.

"I'm accustomed to havng people copy my ideas and concepts and everyone gets ideas from other people," Viguerie said. "But you usually put them into your own words."

Viguerie and Crane parted company last spring and Viguerie has since gone to work as a volunteer for John B. Connally, another GOP hopeful.

"It's hard enough raising money, but it really gets tough when you're competing against yourself," he said. "I feel like I'm raising money for three candidates: Crane, Connally and now Reagan."

After strikingly similar first pages, the two letters depart in language on subsequent pages as Reagan and Crane state the different circumstances of their campaigns.

The tone, however, remains the same.

Crane for example, rails against "the giveaway" of the Panama Canal, high taxes and government spending. So does Reagan. And both end their letters saying, "I'll be anxiously looking forward to hearing from you."