What Master Cylinder for swap from stock power drum/drum to LS1 front/drum rears ...

[BumpaD_Z28]

I did a little searching but never got a definite answer ...

Car has on it now stock POWER drum brakes front / and rear,

GOING to LS1 front brakes (to clear my 16" front wheels) / stock rear drums (for now, gotta find something that will work with C clip eliminators).

Can I use my current Booster, Master cylinder, proportioning valve setup ?

I have heard a certain C3 Corvette master cylinder is the correct bore sizes ???



TIA !

~DaVe

[BumpaD_Z28]

Anyone ? I'm reasonable sure the bore size on my power drum M/C is 1" .. I think it might work ???

~DaVe

[Apogee]

So because you said you're starting with a drum/drum setup, I'll assume you're working on the '67 RS in your signature line. The OE booster/MC combo on the LS1 is a dual-9" diaphragm booster and 1" bore disc/disc master cylinder. A 1" bore MC should work reasonably well in your application, so it's just a matter of finding one that is compatible with your booster. Does it have a long or short pushrod? The 1" C3 Corvette MC has a deep pushrod hole (for manual application), so you'd either need a long pushrod booster or a spacer to make up the difference in a power installation.

Keep in mind that if you run a disc/disc master cylinder, you'll want to add a 10 psi residual pressure valve in the rear circuit to keep pressure on the cup seals inside the wheel cylinders when the shoes retract.

Tobin
KORE3

[BumpaD_Z28]

Thanks Tobin ! and yes I am working on the '67 rs ... right now it has a power booster with a 1" bore M/C, so I think I'll get the brakes done and try it out (pedal feel etc.) and then go from there ...

Still gathering a few items and then I'll give you a call for some more FlexKORE lines !

~DaVe