The Senate voted overwhelmingly yesterday to repeal one of the major tax "reforms" that Congress passed in 1976, a provision raising the tax on the sale of inherited property.

But for the second time in two days the Senate indicated it will not water down the "windfall profits" tax on oil that has been proposed by its Finance Committee.

The Finance Committee's version is already weaker than the "windfall profits" bill proposed by President Carter and passed earlier by the House, but oil-state senators have been trying to whittle it back further -- so far to no avail. In its vote yesterday, the Senate rejected 58 to 32 a proposal by Sen. Bob Dole (R-Kan.) to cut from 75 percent to 60 percent the tax rate proposed for so-called "old oil," meaning oil from wells drilled before 1973.

The vote on the inherited property issue, which was attached as a rider to the windfall bill, was 81 to 4. It amounted to a senatorial slap at both Carter and his main challenger for the Democratic presidential nomination, Sen. Edward M. Kennedy (D-Mass.), who were allied in opposing retreat on the issue.

At issue was the so-called "carry-over basis" rule that Congress adopted as part of its 1976 tax revision program but later suspended until 1980 after lawmakers were pelted with protests, largely from pelted with protests, largely from landed interests.

If the law goes into effect next year, which appears increasingly unlikely, proceeds from the sale of inherited assets would be subject to significantly stiffer capital gains taxes -- fattening the federal treasury by nearly $1 billion a year by 1990.

The Senate's action technically was unnecessary, because a carry-over basis repealer already was included in the Finance Committee's windfall profits bill, thereby making it part of the tax package now before the Senate. p

The vote appeared aimed at strengthening the Senate's hand when it goes to conference with the House on the tax bill. The House has not voted to repeal the carry-over basis rule although a majority of its members have cosponsored legislation for that purpose.

Under the carry-over basis rule, a person who inherited property would pay capital gains tax based on the difference between the selling price and the price paid by its original owner. Repeal would mean that the tax would revert to its pre-1976 status, when it was levied only on the difference between the selling price and the price at the time of the original owner's death.

The repealer was attached to the windfall profits tax bill largely as an end-run around President Carter, who badly wants an oil tax bill but has said he would veto a carry-over basis repealer. The repealer's inclusion in the oil bill presumably makes it veto-proof.

Carry-over basis drew little defense on the Senate floor yesterday. The only senators voting to retain it were Howard M. Metzenbaum (D-Ohio), William Proxmire (D-Wis.), Paul E. Tsongas (D-Mass.) and Joseph R. Biden Jr. (D-Del.). Kennedy was absent for the vote but was paired with another senator who favored the repealer.

Although the windfall profits tax has weathered two weakening efforts so far, there has yet to be a test on whether the Senate will follow the bidding of the Carter administration and strengthen the Finance Committee proposal to bring it more in line with the House tax bill. The committee proposal would recapture about one-third of the profits that oil companies will reap from Carter's phased-in decontrol of oil prices, roughly $138 billion by 1990. This is about one-half of the roughly $277 billion that the government would get under the stronger bill approved by the House.

As the Senate late yesterday began consideration of a proposal by Sen. Dale Bumpers (D-Ark.) to substitute the House bill for the committee proposal, Senate Budget Committee Chairman Edmund S. Muskie (D-Maine) characterized the committee version as a lost opportunity to meet pressing spending and tax relief needs of the 1980s.

"We have mortgaged our future. Without a more productive windfall profits bill, we just can't make the payments," said Muskie. He said the bill's "emphasis on production incentives buys little additional oil at very high cost to the taxpayers" while its "enormous potential for raising revenues is barely approached and it leaves us unprepared for the expenses which lie ahead."

Meanwhile, under heavy pressure from senators who want to grant a tax exemption for interest on savings accounts, Senate Finance Committee Chairman Russell B. Long (D-La.) agreed to take up the issue in committee next week. Among the proposals that will go before the committee is one that would exempt on joint returns the first $200 of savings interest in 1981, rising gradually to $1,000 in 1985.