Brake opinions for my current plan 68 camaro C6 master

[jasonz28camaro]

I have had many issues with my current brake system that has an unknown master cylinder size and unknown combination valve. It’s power brakes with a 7” booster. I’m looking to start over with a new C6 vett master/booster and redo the old brake lines at the same time and would like opinions on the size tubing I selected to see if it will all work together.

My current brakes are LS1 up from and wilwood 12” in the back.
Front and rear have 3/16 coming off the master to the combination valve, dual 3/16 outlet off combination valve to the front brakes and a single 1/4” outlet from combination valve to the rearend where it tees off to 3/16”.

My new plan (currently underway) involves a 2006 C6 master/booster (1” bore) with the same brakes above. No combination valve. I plan on using DSE adapter fittings on the master and running 3/16” tubing. Fronts will have a tee below that will supply each side. The rear will be 3/16” off the master to a proportioning valve hidden on the subframe below then travel to the rearend to a tee to supply both sides.

Concerns:

the C6 master is setup for 1/4” tubing from factory but the DSE fittings I’m using are more or less adapters to allow 3/16 tube and are m12x1 3/16” inverted flare. Would there be an issue if the master was intended for 1/4” tubing, not 3/16? I know this is a common thing people do and must work but I’m just curious.

Am I ok to use 3/16 everywhere or should I use some 1/4” tubing anywhere?

[79 Camaro]

I'm kind of running a similar set up on my 80 Camaro project. C5 brakes all around. C5 booster/2002 Camaro master with the DSE booster bracket. 3/16" and 1/4" into a Wilwood prop valve mounted right below the master. 3/16" lines front and rear. Single front line down to the front cross member and a "t" to left and right calipers.
I done this set up on a number of my hot projects and all have worked well.
See pic of my 68 C10 brake booster.

[jasonz28camaro]

Do you run 1/4” line off the prop to the rear or is it 3/16”? Any particular reason for the 1/4” rear line off the master to the prop valve?

[79 Camaro]

I run 3/16" from the prop valve all the way to the back. Why the 1/4" from the master to the prop valve? It's because the 2002 Camaro has a bigger line and a odd ball flare nut size. It typically have to drill the nut out slightly for the 1/4" line. I think the C5 master or C6 master would be the same.
Again not a great pic but here's a pic of my current 80 Camaro brake setup.

[79 Camaro]

Just a quick note. I really like the ni-copp brake lines. It flares like butter. I buy the 3/16" line in 25 foot sections from Oreilly's. Short pieces like the 1/4" in 2 foot sections. Cut and bend as needed.

[jasonz28camaro]

Thanks. That makes sense. I noticed that the C5s had one big one and one small one coming off the master, must be the same for LS1s. Must be a 6mm tube if you needed to drill to 1/4”. Cool thanks for getting back to me.

[stab6902]

3/16" tubing everywhere will be fine. I don't know why GM elected to use 1/4" tubing to the rears back in the day, but modern cars use bigger diameter tubing between the master cylinder and the ABS unit for extreme low temperature ABS/ESC performance.