With Republican tempers fraying over tax revision, Reps. Raymond J. McGrath and Jack Kemp got into a shoving match yesterday during a strategy session, as top Reagan administration officials looked on.

The spat between the two New York Republicans came at a meeting called to find a way out of the dispute between GOP House members, led by Kemp and Minority Leader Robert H. Michel (R-Ill.), and the White House after Wednesday's vote derailing President Reagan's tax overhaul initiative.

McGrath, one of a handful of Republicans who sided with Reagan and Democrats in voting to bring the issue to the House floor, said he lost his temper when he thought Kemp said "something about me" during a discussion. He said the dispute, while heated, was brief.

"I started it," McGrath said. "I lost my temper, and he did, too . . . . After the shoving and flailing, it was over in an instant." He said others had to step between them and "quiet" the argument. Treasury Secretary James A. Baker III and White House chief of staff Donald T. Regan were at the meeting.

Kemp could not be reached for comment. A Kemp spokesman, John Buckley, denied that Kemp and McGrath shoved each other. He said, "Tensions are very high, but as far as we're concerned, it was a simple misunderstanding . . . ."

"I'm sorry it happened," said McGrath. "We should be bigger boys than to have a fight." The two New Yorkers met later and both apologized, according to McGrath.