Alright, I just did the abs delete. I put a tee in the front for the front brakes, but the rear i hear is metric. I have a prebent 1/4 line for my proportioning valve that needs to hook into the stock metric line. How do I convert the stock metric line to 1/4 line? Is there a fitting or fittings or adapter that I can buy?

You can probably do that with a double sided compression fitting. I used a flare tool that could make both bubble flares and standard double flares and just made a hybrid line - and the fittings are different so you do need the right fittings and flares to make it work or like I said just get a splice.

I talked to another guy thats done his and many on his drag cars and he said it was ok to double flare the factory line and use a 1/4 in nut and use a 1/4 inverted union and another 1/4 nut on the new line..