In the olden days ( 1960) I used to do it the way you did , but now I know better,,, The relay will help carry load better as its connected thru a larger wire from the main power source, I always put the relay near my power source and run maybe 10ga wire to pump. In my case , on my 69, I run electric carter at rear of car, above the rear leaf spring shackle, at gas tank suction level. Placed Relay on cowl with large supply feeding thru relay and using a keyed on signal to close and open relay. This way I dont have all the pump load running thru my fuse block.