Yes, the LS4 5.3s were FWD only, had no provisions for mounting in a RWD car. I went to my local pull-a-part (Knoxville Tn) and found 4 5.3s. Two in Silverado's, one in a Tahoe, and one in an Isuzu Ascender (this is the aluminum 5.3 with 799 heads, the good ones) and I can get the entire engine...