A quick back of envelope sum says that 1013.25mb/hPa = 29.921in.Hg, so 29.92 would give you about 0.9ft error.
Setting 1013 when 1013.25 is technically correct is, according to my calibrated back of envelope, would give you 6.75ft error.
So, I'd say that 29.92 in.Hg is definitely more correct.
G