[JP Noonan]

Besides pressure aren't pumps rated in volume like Liters per Hour? A weak pump can cause a lean (equals boom) condition. The 930 for example has two fuel pumps. I have the following in my car and I think it would work for you.

Carrera fuel pump. you need to buy a "Banjo" fitting with a barb on the end and two sealing copper washers to adapt it to a 914. Or, like me, use a cut off end of a 911 fuel line with the Banjo on it.

3/8" feed lines 5/16" return. Both steel lines to replace my rubtured factory plastic ones. The 3/8" fits fine in 70-74 cars but is a sqeeze in the 75-76 (mine is a 75). I think the older cars have the 9mm-3/8" line as a carry over from the 914-6. Seeing as Porsche thought it neccesary to put a 9mm line on a 110hp (carburated, I'll grant you) flat 6, your turbo will probably need at least this size of line.

MY .02 Lira