I noticed that on 69's (thats what I'm looking for anyway) that some have the proportioning valve on the booster, and some do not. I think its a proportioning valve - it has a large hex nut on the front of it.

If a car doesn't have the valve there, what does that mean (non SS, originally drum, etc)?

Thanks fellas

The piece with the large hex nut is a metering valve, it will be on power disk cars but not power drum.