I would use the later master and move lines. IIRC, there is a difference in bore of the cylinder in the 73 or 74 and later from 7/8" to 15/16" but I have been wrong before and probably are this time.
I would have to look it up to be certain. A common change is to swap reservoirs from front to back and vice versa.
If the 70 model bore is good, sell it over at classic Z's to recover the cost of the changes you make.
From the GCR:
"c. Brake lines may be replaced with steel lines or Teflon-lined
metal braided hose. Lines/hoses may be relocated and may
be given additional protection. Brake fittings, adaptors, and
connectors are unrestricted. Brake system circuitry may be
revised, but no modification or substitution of the original
master cylinder, its location, or mounting is permitted. Cars
with antilock braking systems must disabled
a minimum of
three wheel speed sensors. Components that perform no other
function than to assist in the activation of the ABS portion of
the brake system may be removed."
I say go for it, you are not substituting the OEM master cylinder but revising it. under the update rules.
Paul Ballance
Tennessee Valley Region (yeah it's in Alabama)
ITS '72
1972 240Z
"Experience is what you get when you're expecting something else." unknown
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