depends how you align it 1 or 2 bolts would line up with aid of a rubber mallet hitting down on the rails.
The rears i used galivinized bolts and drilled through the floor boards. I used the stock ep3 rails..
but its better and will align better if you use your ej8 or ek rails on the ep3 seats.
the ep3 seat bucket (square thing under the seat that the rails are bolted to) is tack welded on...you would need to break through those welds..