I rebuilt and marinized a 98 Chevy Suburban 5.7 vortec for my boat. The only marine water pump I could get was the short style which will not fit the smooth water pump pulley off the vortec. I would prefer a ribbed pulley anyway and since I only need water and alt, I won't need to use a serpentine belt. I assume this is not a reverse flow engine so that should not be a problem. I attach a picture to show the alignment problem. One picture shows the old and new pumps.