I wouldn't necessarily be set on an LT1. These days you can find an all aluminum LS1 to pull out of a wrecked car for cheap too or even a newer 5.3 for cheap. I wouldn't pay $750 for one with no wiring harness especially if the word fire is related to it. Finding the right year harness might be difficult because the connections vary a bit from year to year and model to model. You can easily pay $750 for a new harness so I would look for one all complete in the car to pull out everything you need.