[SkinnyG]

I'm at 10.9:1 with iron heads, and it's working on 91 just fine.

You could bump the compression more by milling the heads, but I think you'll be ok for now. If the bottom goes soft, change the pistons at that time.

The cam you picked has an Intake Center line of 104°, which means it's advanced 4°, which is good for low end torque and building cylinder pressure (sort of makes up for the lower compression ratio you have). You'll probably be ok. It has an RPM range of 1700-5700 which is very decent for street/performance/truck. Your 3.73 gears put you right in that cam's happy place. The 108° Lobe Separation Angle gives you a strong but more peaky mid range, at the expense of idle quality and vacuum.

When you don't have enough vacuum to run the power brakes, it just takes MORE pedal effort to slow down. An extreme example: zero vacuum when the engine is off and you're trying to use the brakes.

I've driven some cars where the cam was so big, the power brakes did nothing at a stop light - it took a phenomenal amount of pedal effort just to stay still.

Adding a vacuum canister just increases the volume of available vacuum before you run out at a stop light.

By cam is bigger than yours, and my brakes are certainly adequate - you'll be fine.