I'm thinking they are 1/16 I.D., not 1/8 I.D.
The 1/4 inch I.D. copper line I used work like a charm, it was enlightening how rapid it would change readings when driving the car or revving the motor up out of gear up scope
I was told by a NHRA tech guy later to remove it and put the smaller ling back in that bracket car rant wink
Looking back I should have used a stainless covered #4 AN line and fittings up twocents

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)