does anyone know if the dol is still requiring that prevailing wage plans receive an individual letter of determination? I have been asked to update a davis bacon plan for GUST and wondered if anyone has any up to date info on irs plan filings for these types of plans?

Since these types of plans are considered individually designed, because of the prevailing wage language, I would say that you should submit for a determination letter from the IRS. There isn't any automatic reliance that I know of that applies to these plans.

Since these plans are looked at by the DOL, I would get a "clean bill of health" from the IRS on its form and operation (schedule Q).