Generally, what you are proposing to do is illegal, as stamping the work by others requires "direct supervision", which is not the case if you only review it after the fact. I do recall, though, that Utah had or has provisions for doing this in their state law, so it's not universal. You might check your state's disciplinary actions as well, as this is a common issue.
While poking around in your state laws and rules, I find the following:
"Plans, specifications, plats and reports prepared by the registrant shall be signed, dated, and stamped with said seal or facsimile thereof. Such signature and stamping shall constitute a certification by the registrant that the same was prepared by or under his or her direct supervision and that to his or her knowledge and belief the same was prepared in accordance with the requirements of the statute."
Elsewhere:
"Direct supervision is a combination of activities by which a licensee maintains control over those decisions that are the basis for the finding, conclusions, analysis, rationale, details, and judgments that are embodied in the development and preparation of engineering or land surveying plans, specifications, plats, reports, and related activities. Direct supervision explains the relationship between the licensee and those persons who are performing the work controlled by the licensee. Direct supervision requires providing personal direction, oversight, inspection, observation and supervision of the work being certified.
"Communications between the licensee and those persons who are performing the work include, but are not limited to, use of any of the following ways: Direct face-to-face communications; written communications; U.S. mail; electronic mail; facsimiles; telecommunications, or other current technology: Provided, That the licensee retains, maintains, and asserts continuing control and judgment."
And provisions for reviewing work by others:
"Document review: When a licensee is required to review work prepared by another professional engineer or land surveyor, the reviewing licensee shall fully review those documents and shall prepare a report that discusses the findings of the review with any supporting calculations and sketches. The reviewing licensee would then seal/stamp and sign the report. The report would make reference to and/or be attached to the subject document(s) reviewed."