Installing 5 gauges of which two use the plastic supply line (oil press and vacuum). The plastic tube is coiled and stiff making it unwieldy to use as well as horrible looking. Got rid of the unwieldy coil by slipping it inside of old rubber line I had in the garage. The black rubber line also blends in with the rest of the engine compartment
Yours must be made in China. I bought mechanical gauges back in '81 and they are still working well with no coil bind. I bet mine are more pliable too.
The rubber should protect the plastic and help increase its life span. Some of that plastic line doesn't like being exposed to the elements, and the rubber should help that.
I used AN #3 fittings & #3 Lines, T- it off the engine so you can still use the Sending unit. (Oil) Clean Install.....
I dislike the looks of plastic line but in my experience if you make sure it's routed away from heat and doesn't chafe on anything it'll last pretty much forever. I've run it several hundred thousand miles on many of my vehicles as well as in customers dirt track cars and my road race 2nd gen. Copper looks a gazillion times better but you have to be careful of how it's routed and clamped. If it flexes over a short length it'll work harden and crack. You can run braided to a bulkhead on the firewall for both good looks and durability but the cost get's pretty close to a good full sweep electric gauge at that point.
