Have an 84 Trans am. In the middle of an engine swap with a Jegs crate 350. Putting Fitech fuel injection on it. Jegs sent a giant fuel pump assy, can't remember the brand right now. Was wondering if I can use an in tank electric fuel pump as long as it has enough pressure. Will an 85 up sending unit work and what is the difference between 82 to 84 and then 85 up. Is it form or just connection differences. Seems 84 is not available at all.