HELP, hard brake pedal and low vacuum reading

[Cinpro]

I have been chasing down a hard brake pedal issue. th car has an L61 with stg1 compcams, intake 4-2-1 header, msd ign. the car had been parked for awhile and it thought maybe something had tried to seize up on my from being parked, so I checked my calipers and lubed all slider pins, still hard a pedal. next i checked the booster check valve and its good, air only goes one way, and there is the normal suck sound of the vacuum breaking when the line is removed. I got a vacuum gauge and hooked it to the manifold where the purge valve hose normally goes. i get a reading of 8-10" with a steady fast flicker, goes almost to zero when accelerated, if I move the gauge to the FPR with a tee in the line it goes to 10-12" still with the fast flicker. i think the fast flicker is due to the hotter cam, could it be late valve timing? I thought i misaligned something before and redid the timing 10-2-5, number one piston at TDC. throw all your ideas out there, I'd like to get this resolved before it gets to cold for me to work on it as I don't have a garage, and its already starting to cool off.

[montecarloman]

Was the car running perfectly fine before? What did you remove to install the cams?

Some vacuum leak somewhere is most likely. Timing could still be incorrect or you could have a misboxed cam/cams. Thats very unlikely but possible.

[billabong9687]

with cams, vacuum will chang., the valve over lap changes when you add larger cams with different lobe seperation angles. However 8-10 seems pretty low unless they are MONSTEROUS

Low vacuum can also be a resulst of improper cam timing, a weak cylinder: due to rings, or valves sealing properly

[Cinpro]

the brakes had been fine, the engine was a bit rough due to needing tuning, however it wasn't being driven. I been in the hospital almost as much as I've been out, and haven't been working on the car again until recently. I've mostly been planning for future upgrades and reading a lot. going to test the manifold for a leak tomorrow, if thats not it I'm going to park it till the new block and head are back from the machine shop and be on my way to starting fresh with all new internals and timing. I was planning to do the build over the winter in the basement shop anyway.

[billabong9687]

Does the idle hunt at all? you would need a HUGE vacuum leak to loose booster assist. Trust me, you would hear it also.