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720 brake booster in a 620?


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Negative! The 720 booster is huge and sits on a pedistal 8-9" away from the firewall. There is even a dimple in the inner fender to allow this. The reason this is possible is that the Z series motors have their intake on the pass side and with only the small exhaust manifold, there's plenty of room on the driver's. The pedistal allows room for the clutch master and places the large diameter booster out in front of it. If some way could be found to move the clutch master over a couple of inches you could 'squeeze' it in, but without the long pedistal, as it would hit the stock L intake let alone the air filter.


I agree it is a good question. Would love to use a 15/16 or 1" M/C but you would need a larger booster than the stock 620 one for sure. I've got 2 or 3 720, 2 '80 200sx, an '80 280Z, and at least 3 620 M/Cs all with boosters, and I'm still trying to come up with something. Did not notice clearance issues with the steering column Beebani, but it's easy to overlook. I have a 720 column in there, maybe its at a different angle. It has a U joint into the P/S unit.

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I am using the 15/16" master from a ZX on the stock 620 booster. Bolts right on and works perfect. I have about 20k miles on it like this so far. The pedal is a little stiff, but so much better than the 13/16" stocker. I would not go to a 1" bore though.



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Maybe you guys could get a vacuum pump off a s12 turbo, hook that up to the master instead of the intake. Maybe it would create the effect of a "bigger" booster.

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So, you know for sure that the 720 m/c won't work on the 620 booster? I have the 720 m/c already, just trying to decide which booster to use.



Beebani your post said: Has anyone ever tried to bolt a brake booster from a 720 into a 620? Just curious what the size difference is.


The 720 booster won't fit into the 620, as I said. The M/C would though. Some have vertical and some have horizontal mounting bolts onto the booster. Some have an adapter to use either.

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