With a minimum of rancor and the first significant Republican support for a Congressional budget, the House yesterday passed a tentative 1978 budget that sets a spending level of $460.95 billion and a deficit of $64.65 billion.

The vote was 221 to 177, with 29 Republicans voting with 192 Democrats. In all five previous votes under the two-year-old budget process, fewer than a dozen Republicans have voted for the final resolution.

The Senate, where support for the process has been bi-partisan, passed an identical resolution last Friday. The Congressional budget does not need a Presidential signature.

President Carter has recommended his own budget to Congress. The President's budget has a slightly higher spending level than Congress's, but because Carter expects a better economic performance - which results in higher tax revenues and lower payouts in programs like unemployment insurance - he expects his budget would have a deficit of $57.9 billion.

The Congressional budget approved yesterday by the House is only a target, to guide Congress in allocating funds over the summer. The Congressional budget and the Carter budget are similar except in defense and education. Carter is higher in defense; the Congress is higher in education.

Legislators must agree on a final, binding budget by September 15.

Although the final, compromise budget passed both the House and Senate easily, there was tough going in the House at first and House-Senate conferees deadlocked for nearly three days over the proper level of defense funding for fiscal 1978, which starts October 1.

In the House three weeks ago the first try at a 1978 budget was defeated, as liberals were displeased with high defense spending and conservatives disliked the big deficit. A compromise passed the House a week later.

Rep. Robert N. Giaimo (D-Conn.), chairman fo the House Budget Committee, called the House-Senate budget a "realistic and reasonable compromise" between those who would spend more for social programs and those who want to increase military spending.

But many House liberals, including budget committee members Rep. Parren Mitchell (D-Md.) and Rep. Elizabeth Holtzman (D-N.Y.), voted against the budget because the conference boosted defense spending and lowered human needs spending.

Many Republicans who routinely voted against budgets in the past, such as Rep. Marjorie Holtz (R-Md.), voted in favor of the budget this time.

Holt said yesterday that if Republicans are going to be a part of setting priorities, we've got to get in and be active in the budget process. As they say in my state's lottery, 'You've got to play to win.'" That brought some applause from the Democratic side of the aisle.

Some Republicans have worried that because the party always votes against the budget, Giaimo and the Democratic leadership are always forced to make alliances to attract liberal Democrats. "We're telling him he can move to the right and pick up votes now," one Republican said privately. House minority leader John Rhodes (R-Ariz.) was one of the 29 Republicans who voted for the budget.