Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
London Underground C69 and C77 Stock
Table title:
Numbering
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=2 rowspan=2 > Formation </th><td colspan=2 rowspan=1 > Reversible units </td><th colspan=1 rowspan=2 > Notes </th></tr>
<tr> <td colspan=1 rowspan=1 > 5xxx (DM) </td><td colspan=1 rowspan=1 > 6xxx (UT) </td></tr>
<tr> <th colspan=1 rowspan=3 > Numbers </th><th colspan=1 rowspan=1 > C69 </th><td colspan=1 rowspan=1 > 5501 : 5606 </td><td class="highlighted"  colspan=1 rowspan=1 > 6501 : 6606(1) </td><td colspan=1 rowspan=1 > 5585(1) destroyed in 1975. 5505 partly destroyed in 2005 - rebuilt as 5606(2) 6505 renumbered 6606(2) in 2008 </td></tr>
<tr> <th colspan=1 rowspan=1 > C77 </th><td colspan=1 rowspan=1 > 5701 : 5733 </td><td colspan=1 rowspan=1 > 6701 : 6733 </td><td class="highlighted"  colspan=1 rowspan=1 > 6713 partly destroyed in 2005 - rebuilt as 6734 5713 renumbered 5734 in 2008. </td></tr>
<tr> <th colspan=1 rowspan=1 > C08 </th><td colspan=1 rowspan=1 >  </td><td class="highlighted"  colspan=1 rowspan=1 > 6606(2) 6734 </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
What were the remains of the London Underground C69 and C77 Stock used for in which new cars?
Answer:
The remains were used in the building of new cars 6606 (the second car with this number) and 6734.