Originally Posted by
LS-SWAPPER
This is few months old, but I'll throw in my $0.02 in case someone else is reading. The 8.1's that I have seen from the 2001-2002 range have a unique DBW TB, it is wide with the motor sticking to one side. Similar to an LS1 dbw vette, but the motor is on the opposite side iirc. Later on 2003 or 2004 it seems the 8.1s got the more squared off DBW TB like we see on all the 2003-2006 4.8/5.3/6.0s.
The 8.1s would have had a 4L80e behind them in the right application. Models that I am aware of are a 2500 Suburban, Avalanche, or Van. As far as I know none of the actual Silverado trucks with the 8.1 had anything other than an Allison.