got my 86 out of the underground parking. Had to boost it to get it started. When I pushed on the brake pedal, it died. Had to boost it again. Did a full battery charge, but I notice when I push on the brakes, the battery indicator drops by 2 volts. Do I have a short?

 

your air bypass valve could be clogged or your alternator could be dying. The Air bypass valve is that blue thing attached to the drivers side of the intake manifold, you can remove that and clean it if you're mechanically inclined. Get an AVR test done to test the alternator.
Edit:
Actually since it's the voltage that is dropping check that the white connector is plugged in at the back of the alternator... that is your voltage regulator wire

 

Uh, did you perform any proper storage techniques at all?

Assuming the battery was left in the car all winter, and was stone dead when you tried to start the car, I'd first start by buying a new battery. Lead acid batteries don't like being stone dead for months in sub zero temperatures.

If the car wasn't properly stored than you may be facing other problems as well. Best to perform a full tuneup at this point.

 

I would see if any of your vaccum lines are broken as well as get that battery checked out.
I would have to agree with aaron, start with the easy stuff first and if your gas is old then???

 

Personally I wouldn't have left the battery in the car over the span of Storage.
It is always "wise" to get a trickle charger and plug it in, to keep the battery maintained over storage or take it out and maintain the battery at home.
Take the battery to Canadian Tire,as they would 'just Love" to sell ya one!(haha)..and have them do a Current draw or an AVR (Amp,Voltage Resistance test.,.) on it.
If the battery is Toast then you have the option of buying one.If it is Good then walk out of the store!!!

 

I have been storing this car for the last six years, underground parking, gasoline additive, starting and moving monthly. After fully charging the battery, I got 12.6V on the battery, and 14.8V when running. I replaced the battery (Crappy Tire) last year. I am just worried that I will be left stranded with a similar no start.