Replaced the copper fuel line with 1/2" DOT Nylon tubing, from the fuel tank to the primary filter, and from the primary to the IP booster pump... I used a flared 1/2" copper stub from the pump plate fitting to a 1/2" compression union (there's an extra flared copper stub in the picture, so you can see what I mean). l I taped both ends of the tubing roll shut before I started so I wouldn't get any crap in the tubing while routing it along the frame rail, and covered the tubing in 1/2 ID rubber hose anywhere I thought it may get any significant abrasion...
The connection from the new tank tubing to my spin-on primary base inlet was easy (yours may be different) 1/2" male pipe thread on one end, 1/2" compression on the other end, old vs. new...
The connection on the outlet side of the primary is basically the same, 1/2" male pipe x 1/2" compression, it's just a 90* elbow instead of straight fitting. All the pieces in the pic on the right were replaced with one piece of 1/2" nylon...
The IP fitting was a bit harder to find than the others. 1/4" male pipe thread on one end, 1/2" compression on the other (seems like you can get fittings that jump one step at a time easy... i.e. 1/4 to 3/8, but the 1/4 to 1/2 seemed to be not as common). Did away with both the copper and hose between the primary and IP, and just made it one-piece of 1/2" nylon tubing. Got the fitting at;
https://www.napaonline.com/en/p/WH_68X8X4 ...