I wish I had used the Mercruiser fittings and lines. I became a virtuoso line bender making up lines for two different carbs and two different fuel pumps.
I'm so bullheaded, I had to do it myself. Waste of time and money in the long run, but they are done and nice now!
I ran an Airtex for 2 years. Pulled it when I had a different problem. I'm sure now that I didn't have to toss it. But it's gone now.
I wasn't satisfied til I got a Holley Marine pump, which is rated for everything my carb could demand. It seems not to drain back, much if at all. If I don't run the boat for a week or so I get fire in 3 or 5 seconds of cranking. If I watch the fuel pressure gauge it jumps around for a good 10 or 15 seconds til the bowls are full and things get steady. But the engine can't tell, so it must be getting fuel.