I know we've talked about the a-arms but I found this bulletin from GM.
<FONT face="Arial, Helvetica, sans-serif" size=2>Engineering has changed the
design of the lower control arm used on C/K HD trucks and the HUMMER
H2.
The original A-shaped arms for the C/K HD were p/n 12475475/76 and
88982348/49 for the H2. The service arms for all vehicles are now the V-shaped
arms.
The V-shaped arms are direct bolt-in replacements and require no
special treatment; they simply look different. The new V-shaped arms are p/n
15103878/79 for the C/K HD and 15103880/81 for the H2.
<FONT
color=#ff0000>TIP:</FONT> These are the production as well as
service part numbers and should not be mixed. The bushing rate for the H2 arm is
much firmer than that of the C/K HD.</FONT></P>
<FONT face="Arial, Helvetica, sans-serif" size=2></FONT><FONT
face="Arial, Helvetica, sans-serif" color=#666666 size=1>
- Thanks to Steve
Love and Dan Stress</FONT></P>
<TABLE cellSpacing=2 cellPadding=2 width="95%" align=center border=1>
<TBODY>
<TR>
<TD width="34%" rowSpan=2>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif" size=2><FONT
size=1><FONT size=1>
</FONT></FONT></FONT></DIV></TD>
<TD vAlign=center align=middle width="28%" height=77>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif" size=2>Service
V
Arm</FONT></DIV></TD>
<TD vAlign=center align=middle width="18%">
<DIV align=center><FONT face="Arial, Helvetica, sans-serif" size=2>C/K
</FONT></DIV></TD>
<TD vAlign=center align=middle width="20%">
<DIV align=center><FONT face="Arial, Helvetica, sans-serif"
size=2>15103878/79</FONT></DIV></TD></TR>
<TR>
<TD vAlign=center align=middle>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif" size=2>Service
V
Arm</FONT></DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif" size=2>HUMMER H2
</FONT></DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif"
size=2>15103880/81</FONT></DIV></TD></TR>
<TR>
<TD rowSpan=2>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif" size=2><FONT
size=1><FONT size=1>
</FONT></FONT></FONT></DIV></TD>
<TD vAlign=center align=middle height=83>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif" size=2>Original
Service
A Arm</FONT></DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif"
size=2>C/K</FONT></DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif"
size=2>12475475/76</FONT></DIV></TD></TR>
<TR>
<TD vAlign=center align=middle>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif" size=2>Original
Service
A Arm</FONT></DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif" size=2>HUMMER H2
</FONT></DIV></TD>
<TD vAlign=center align=middle>
<DIV align=center><FONT face="Arial, Helvetica, sans-serif"
size=2>88982348/49</FONT></DIV></TD></TR></TBODY></TABLE>
</P>