This "while the engine is out" project seems to have no end.

I was going to replace all the brake lines from proportioning valve back. Now I am thinking that it may make sense to do the lines that run through the center tunnel. At the same time, with costs adding up is it overkill.

I see several threads on the fuel lines but none in the center brake lines. Is that because it is super easy (just pull the through rear or front). Or is it that it is either a real pia or something rarely needed?

Finally, I do have an NOS proportioning valve but it is the late style without the "T". If I ordered late style rear lines would it be an easy switch or did various mounting tabs, holes on car body also change.

Thanks yet again.

I always thought the brake lines were the same across the year models. I guess I am wrong?

If you look at the diagrams you will see different pressure valve and rear lines from that valve. The change took place some time in 1974 and part numbers are different.

What I am not certain about is if you can simply use a newer valve by switching to the newer lines from valve to rear of car. I do not know if other mods were made to the body such as position of the valve, position of line routing through firewall, position of rear line retaining tabs.

I am already way over budget so if I can use the later NOS valve I have on the shelf, that saves some $$$. Worst case, I will get my original rebuilt and sell the NOS one on evilbay.