The Stovebolt Site Forums The Parking Lot Big Bolts thoughts on brake hose diameter

If this is a measured ID from the original hose there could possibly have been some expansion over the years...never heard of this but possible I suppose.

I would not think this would affect performance at all. The only effect this could possibly have would be to slow the application of the brakes slightly by reducing how quickly the brake fluid can move through the hose. In a laboratory setting one may be able to measure a difference in the flow rate of the different hoses but in a real life application I can't see it would matter.