I'm doing the brakes on my rpu and according to the Vern Tardel bible he claims to use 3/16 line on the front and 1/4 on the rears. My old parts car 39 has 1/4 inch line for everything. Every old ford parts book just list 1/4 inch line also. I'm wondering if its cause he used self energizing Lincoln brakes on the front, although you use the same slave cylinders on non-self energising as they do on energizing brakes. I'm wundering what some of yous guyz been using for brake lines?