Phil if you are using the stock fuel pump that circuit does not need a relay, I seem to remember my fuse for the pump only being a 1 or2 amp (I do sometimes suffer from CRS, ask my wife
) you can use that as a pre-delivery pump as your new FI swapped engine will need a High Pressure pump (40, 45# if I had to guess*) which you could mount up front and I would expect that pump too have a better electrical appetite (5 to10 amps) and that should use a relay. As for merging the two systems that will need a little more thought, and maybe some diodes or multiple relays to prevent any possible back feeding situations that could arise. Harry
*I didn't think about yours being pressurized, so yes it would need a even higher pressure pump as you state ahead
I'm not a hoarder I'm a preservationist 78 Monza Spyder (~Soon(ish +/- I guess) To Be 2+2 with Spoilers)