Senate Finance Committee Chairman Bob Packwood (R-Ore.) was presented yesterday with a set of staff-drafted tax proposals that would postpone the effective dates in the House-passed tax legislation by as much as a year.

If the new deadlines remain in the draft, which Packwood is to show to committee members later this week, they could increase the widespread confusion in the business and financial communities about whether transactions are covered by the current tax code or a new law.

The effective date for most provisions of the House legislation is Jan. 1 of this year. Finance Committee members have said they do not want to approve legislation with a retroactive date of implementation.

The draft proposal, which Packwood has not yet approved and which still is subject to change, would cut the top tax rate for individuals and corporations to 35 percent. In the House bill, the top rates are 38 percent for individuals and 36 percent for corporations. Individuals currently pay up to 50 percent; corporations, 46 percent.

Packwood has said he wants to propose limiting the deduction individuals now take for state and local sales and personal-property taxes.

Like the House bill, the draft plan would bring in roughly the same amount of revenue as the current tax code, raising taxes in some sectors to offset the revenue lost from cutting tax rates. The principal revenue-raisers were said to include the disallowance of 10 percent of the deduction for interest paid by businesses, limits on the deduction for business' advertising expenditures and the denial of the deduction for excise taxes paid by businesses.

Those provisions, which could raise more than $80 billion over five years, are sure to be controversial if they are proposed to members of the Finance Committee. They appear to strike particularly hard at retailers and other service industries, many of which support the House tax bill.

"You could almost view it as a well-calculated effort to kill tax reform," said one business lobbyist who supports the House bill.

Those and other increases in business taxes would shift the tax burden to companies from individuals by at least the $122 billion over five years that was proposed by President Reagan, although probably by less than the $140 billion shift in the House legislation, sources said.

The Senate staff plan also was believed to give companies more generous write-offs for investment than the House measure. But the investment tax credit, which subsidizes up to 10 percent of the cost of equipment and machinery, was expected to be proposed for repeal.

The package was said to be easier on U.S. companies with operations abroad than the House bill, although it was believed to be tougher on taxation of foreign firms with operations in the United States.

A lower tax rate for increases in the value of assets held by companies -- corporate capital gains -- was likely to be retained in the Senate draft, although it was repealed in the House bill. Timber, a home-state industry for Packwood, benefits from corporate capital-gains treatment. The percentage-depletion deduction for oil and mineral extraction also was believed to be retained in the proposal.

Committee aides would not comment on details of the draft, which Packwood plans to discuss with Treasury Secretary James A. Baker III as early as today. But other sources were willing to provide information and informed speculation about the package.

Packwood was said not to be concerned about a letter signed by 11 of the 20 Finance members asking him to delay committee bill-writing until confusion over effective dates is resolved, presumably by a statement from Packwood and House Ways and Means Committee Chairman Dan Rostenkowski (D-Ill.) setting new dates. Aides said the new effective dates in the draft would help ease that uncertainty.