\'72 blazer tailpan replacement Hi-New guy on board-Need to replace rear floor section & rear cross sill/tailpan on '72 K-5. I have a decent rear cross sill from a '72 fleetside longbed. Looks the same except where K-5 is notched for frame ends & boxed where rear body mounting bolt/cusions go? Anyone know if this truck piece will work or do I need blazer piece? Thanks for any info.