M113 5.4L V8 engine swaps

A recurring modification is dropping the 5.4L M113 in place of the 4.3, since the 43 and 55 engines share dimensions and bolt straight up and pass emissions on the stock ECU; owners claim it beats period rivals. Value opinion is split, with purists arguing the loss of original equipment makes such a car 'worthless' while swapped cars still sell in the roughly $9k-$20k range.