Can't find any 3/8 brake fittings for 1/4 line

[64stpside]

Sigh........this is getting frustrating. I got the front 2 lines off the wheels done up to the t fitting using 1/4 line using 7/16 fittings. The top port of the same t fitting that goes to the mc has a 3/8 fitting size. I went to 3 parts stores to get a 3/8 fitting for 1/4 line and nobody has them. I can't find any thing online either. I'm about ready to go 3/16 all the way around because I'm not using adapters on every port that takes a 3/8. If anyone has a place to get the 3/8 fittings for 1/4 line please let me know.