How to remove lines with nonsense format numbers?

I have the following data that I am processing to get the 1st and 5th column, convert the D format to E format and delete rows that have gibberish numbers such as 9.410-316.

DEG =      1.500
	 2.600D+01     0.000D+00     0.000D+00     0.000D+00     0.000D+00
     2.700D+01     8.720-304     2.369-316     7.556-316     9.410-316
     4.300D+01     1.208D-83     4.156D-96     7.360D-96     6.984D-96
     1.590D+02     8.002D-07     6.555D-19     7.748D-19     7.376D-19
     1.600D+02     1.173D-06     9.669D-19     1.143D-18     1.089D-18
     1.610D+02     1.709D-06     1.417D-18     1.676D-18     1.596D+01
     1.620D+02     2.468D-06     2.058D-18     2.436D-18     2.320D-10
DEG =     18.500 
     2.700D+01     2.794-314     0.000D+00     0.000D+00     0.000D+00
     2.800D+01     4.352-285     1.224-297     3.685-297     4.412-297
     8.800D+01     1.371D-02     6.564D-15     7.852D-15     7.275D-15

My problem is in identifying the number formats that I want to delete. So far, I have tried

-bash
maxa=18.5
maxangle=$(printf "%.3f" $maxa)
if (( $(echo "$maxa 10, else only 5)
else
  txt2search="DEG =     $maxangle"
fi

line=$(grep -n "$txt2search" file  | cut -d : -f 1)

# Once the line number is read for the string, skip a few lines (4) and read next several lines(1000)
beginline=$((line + 4))
endline=$((line + 1002))
awk -v a="$beginline" -v b="$endline" 'NR==a, NR==b {print $1, $5}' fileinput > fileoutput
sed -i 's/D/E/g' fileoutput

Then, to discard the rows with the nonsense numbers, I tried (one at a time) and failed with the following commands.

-bash
sed -ni '/E/p' fileoutput
sed -E '/(E)/!d' fileoutput > spec2.tempdata
sed '/E/!d' fileoutput > spec2.tempdata
awk '!/E/' fileoutput > spec2.tempdata

How can I identify and remove lines with such nonsense numbers? The versions are * sed (GNU sed) 4.7 * grep (GNU grep) 3.4 * GNU Awk 5.0.1, API: 2.0 (GNU MPFR 4.0.2, GNU MP 6.2.0) The output would be

2.600D+01     0.000D+00     0.000D+00     0.000D+00     0.000D+00
4.300D+01     1.208D-83     4.156D-96     7.360D-96     6.984D-96
1.590D+02     8.002D-07     6.555D-19     7.748D-19     7.376D-19
1.600D+02     1.173D-06     9.669D-19     1.143D-18     1.089D-18
1.610D+02     1.709D-06     1.417D-18     1.676D-18     1.596D+01
1.620D+02     2.468D-06     2.058D-18     2.436D-18     2.320D-10

**EDIT:** The solution that I was looking for is (see first comment)

-bash
grep -v '[0-9]-'