how do you get to the pump to change the impeller on the 1998 25 agressor 454 mpi it is way down under where you can barley see it.

I am not sure where it is on your Aggressor, but, I have a 454EFI in a 96 Baja and the pump is mounted down low on the Starboard side, the way I change it is to lye "across" the motor, with my head just over the pump and reach down and change the impeller, I did it last year [on a trailer] at nite, in the rain [DONT ASK! LOL] using just hand tools and the lights I have mounted in the engine area and it only took about 45 mins.

The EFI motors are MUCH more comfy to lye on, no carb, carb stud or sharp linkage stabbing you in the stomach!