I have problems with the power brakes on my 68 charger. I think this is due to the cam I have as the brakes work find when the first time I apply them from a cruising speed but the vacuum doesn't seem to keep up if I am in traffic or for any multiple brake pumping. I see they make electric vacuum pumps for such a problem. Do they really work?

Bunch of OEMs are still using them on applications with little vacuum like Turbo cars or 5cyls (or both, lookin at you Volvo).

We have one plumbed in on the 72 charger. Got some one way in line valves from a Honda (I think) so I could have both it and the motor vacuum pulling on the booster.

Haven't got it street legal yet but driving around pit roads can be a lot of stop and go and so far so good.

Diesels either must use a hydroboost or a vacuum pump, one or the other

Yes they work. I pulled a couple from Cadillacs at our local pull a part and mounted one behind the headlight bucket on the drivers side. Works just fine. Its noisey until I fire up the engine then I cant hear it. I needed to take my cordless drill to remove them as you have to drill out the mounting plates. Take it all if this is the way you go. The mounting plates are specific and include rubber mounts to cut down on the noise.

I have used new ones from summit if you want to go that route. Yes they work. Yes they are noisey until they pump up. Billet one is $$$ but looks good. I think they have a lower price unit also.

I ran a 263 @ .050 on my GTX on the street I just set my idle to 1150 in gear and it was fine.
Still run the power with a 272 @ .050 cam got the isle at 1250 in gear. stops me from 130. fine in te pits and return roads.

but going to standard brakes next spring

I was planning on going with standard brakes but a friend of mine is trying to talk me into the vacuum pump. It has been many years since I have driven something with manual brakes but I don't remember them being all that hard to push. I suppose I could try getting one out of an old cadilac or a different vehicle. I saw them at summit for around $300 and don't really want a $300 experiment to find out I don't like the vacuum pump, that is why I may try the cadilac route first.

You can always dial in your pedal feel on a manual setup by trying a master cylinder with a different piston diameter. Dr Diff sells aluminum MC in like 4 different sizes. Shaves a couple pounds and no rust as a bonus.

With enough intial timing, you should have enough vacuum for brakes.

Probably why mine PB always worked 38 to 40 degree's all in by 1200?

I paid $20 bucks for the two I got, including all the electrical connectors, etc. Even if the diapram is blown you can make a diaphram outta an old inner tube to fix it. It will not effect braking if it blows they'll just go back to being hard to push.

I have mine off of a 78 Cadillac DeVille. I got three from a boneyard and pieced one together to make it work. Still going after 8 years. I have it mounted under my battery tray with a one liter vacuum canister in the wheel well. Is a bit noisy on startup until the engine kicks over....and I have but an Isky 280/480 MegaCam in my Charger.