I just did a motor swap in my 92' Camaro RS to a 358. I have an edelbrock performer rpm and a comp xr270. the intake is only making 6lbs of vaccuum for the brake booster. normal is around 24-30. what could be the problem?

 

Too big of a cam/engine combo. Look into an electric vacuum pump and reservoir to hold more vacuum.

Ed

 

what is the duration of that cam? I doubt its too big.

 

That's the same cam I'm running and have at least 15" of vacuum at 750 RPM idle and no problems with my power brakes. You have a bad leak somewhere. Maybe you're brake booster is busted, or your vacuum gauge is. At 6" of vacuum, the engine will be running like total crap.

 

I did realize that we had a port used for cruise control but we took cruise control out. So thats 12" of vaccumm leaking.. But do you think theres more to it? * and the motor does seem to run rough

The cam is a Comp XR270
Intake is Performer RPM

 

Yes, that's the same cam & intake I'm running.

Are you sure all the unused ports & intake are plugged? If so, then you have a cracked hose somewhere.

 

We did degree my camshaft 2 degrees retarded. I'm not sure if that would make a vaccum difference? It makes a top end difference though