Does installing a High Rise Intake on a BB Make your Powerbrakes weaker

[ACUDANUT]

 I have a Mopar Performance High Rise intake installed on a HP 383...I swear it makes my PB suffer. 

[b5blue]

Use a vacuum gauge to read how "much". When I had a 509 in my 440 it was lower than now, but they worked together. I added a vacuum reserve can to give my boost a kinda 2nd shot of vacuum. Before I did this it would build up vacuum for 1 shot on the brakes but repeated braking it would loose boost. You may be loosing the volume of vacuum needed.     

[flyinlow]

If all you changed was the intake I would not expect any significant difference in the manifold vacuum readings. Dose the engine  idle normally? A larger plenum unheated intake might require a richer ilde mixture.

When you rerouted the powerbrake vacuum line, it did not get pinched or restricted by chance. If the line is pulling on the check valve it maybe letting air in around it. PB boosters need at least 10-12 inches to operate.

[doctor4766]

I'd be looking for an air leak. Sounds like you're loosing vacuum somewhere there.
Perhaps the pan gasket hasn't sealed properly or even the carby to manifold gasket could be leaking effectively robbing the booster of much needed vacuum.
You can test for leaks somewhat by spraying some carb cleaner or WD40 near suspected areas and see if your revs increase. Use the nozzle tube though to be more specific where the spray goes.

[ACUDANUT]

 Car runs like a dream race car.  No pinched lines or any of that. New booster and master cylinder too.  How can you get a secondary Vacuum booster.

[flyinlow]

If the check valve on the power booster is working correctly it with hold about two brake applications. You can add a vacuum storage tank and check valve that will give you more applications before it needs to be recharged with manifold vacuum above 10-12 inches.
It is usually big overlap cams that cause low idle vacuum causing PB issues. More intial timing can help bring the idle vacuum back up if that is the problem. Higher idle speed can help with the low vacuum ,but you have to balance that against other concerns. 

[doctor4766]

Yep true.
I'd be buying a vacuum gauge anyway and tuning for maximum vacuum from both timing and mixtures.
If all else fail you can buy a vac pump to aid the brakes. I havent had much success myself with vac tanks. Mind you, having the wrong camshaft didnt help my cause either. I ordered a resto magnum cam but was supplied a 509 lift in the box.
Couldn't use the booster at all and had to resort to manual brakes again until we finally resolved the issue.
Wasn't happy when I found out MP sometimes label their parts wrong.