Aluminum Master Cylinder ?

Which is the front and rear brake line coming out of the MC? Can't find my reference part. thx matt

Larger reservoir is the front brakes.

Normally the front port is for the rear brakes and rear port (closest to the firewall) is for front brakes.

Thank You guys matt

As said the larger port is always for the front brakes & will always be next to the firewall & if both are the same size then same thing, the one next to the firewall will be for the front brakes. OT If you are useing 73-76 A body calipers be sure to ask for ones for a '76 A body as they have a larger bore (2.75" as opposed to 2.60" for '73 -'75) which gives more front bias, always a good thing.

....and I'll be adding my adjustable proportioning valve on the rear line (front brakes). Just in case you needed more stuff to think about

Most of the smaller bore aluminum chrysler based master cylinders have no bias. For example, pre abs Caravans had cross braking hydraulic systems. Each port on the master cylinder controled one front brake, and the opposite rear brake.
This is not to say they cannot be used on a front to rear split system, but understand that there is no bias built into MOST of the non truck masters.