power brake booster

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Your cam specs are 274/284/110 and 224* @050; with lift of .538/.534..That is a pretty nice street cam.
That dual diaphragm was barely ok with my 223* cam. After doing all the external checks and finding nothing wrong with mine,I took mine apart to prove it was ok. And it was.So I drove it that way. It was lazy from time to time. Lazy meaning slow to build boost if too much time spent at low rpm. When I went to the 230* cam it became intolerable. It may be that your idle vacuum is a bit low to charge the chamber. It may be that your checkvalve is leaking. It may be that the pushrod adjustment is in need of changing. Or it may be that your booster is just not up to the task.. There is enough info in this thread to determine which it may be.

From your description, I think I would swap it out; but be prepared to fine tune anything you replace it with.Best of luck to you. Nice cam. She wants about 14* minimum initial timing to build vacuum and a fairly slow rate of advance to prevent detonation. I ran mine on 87E10 with aluminum heads and 10.7 C/R.I really loved that combo.Gobs of torque and great gas-mileage.T
 
If you need more vacuum than your cam provides, you can install an electric vacuum pump. After-market ones cost ~$300. Recent diesel cars (VW, Audi, ...) use them and are ~$50 used, but you need to wire a vacuum switch ~$30. Another option is a non-vacuum booster, using your power steering fluid (if you have), termed "hydro-boost". Those are much smaller than a vac booster.
 
Power assist brakes are always harder to operate in a lack of power condition regardless of the power type/source.
On the flip side, basic manual brakes ( with the right master cylinder bore ) can be very sufficient and with a very practical price too.
 
Also keep in mind that as soon as the engine speed comes off idle, she begins to make vacuum and with a 274*/224@50 cam, and decent initial-timing, you should have plenty of vacuum, by 1200rpm. Plenty enough for a single diaphragm like the 73Dart one that is on my car.The thing is to make sure the check valve is working.I have a slightly bigger cam;276/230@50 and there is absolutely no issue.I was able to get the Dual diaphragm to work with my smaller cam;270/223@50
 
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RedFish said:
Your money, your choice. One year warranty. 3, 5, 10, year later who will be willing to rebuild it if they don't even know what it is. and brake fluid on chrome hasn't worked out well in most cases. those purdy chrome master cylinder covers are short lived.
Click to expand...
They also sell one that is not chrome so I would probably go with it. I am more interested if anyone has bought one from this company
 
Just a FYI, Jegs has the Right Stuff Mopar 8'' Dual Diaphragm #965-RPB 8001 for $159.71... Just a thought..
 
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