rmoths

I bought a 72 Cutlass (350), The motor is rebuilt with roller rockers and for sure not a stock cam. I have poor vacuum to my brake booster, about 9-10 pounds. I've seen in this forum that happens with larger cams. My brakes are not the best ,Not dangerous bad but could be better. Just wondering if there is something I could do to get more vacuum to the booster or maybe a different booster would help. Thanks Barb.

hookem horns

Might get by with an aftermarket vacuum cannister, or make sure with an electric vac pump. Check Jegs or Summit. Power brakes will not make it stop better, just easier.

JPMDaddy

tried an electric vacuum pump from JEGS on my el camino - SO LOUD I could not hear the long tube headers with Flowmasters

Fun71

How is your distributor set up? I ask because when I installed a larger cam in my engine the vacuum was ~10-12º, bounced around a lot, and the brakes didn't work as well as they did before. I was able to increase the idle vacuum to a steady 16" by modifying the distributor so the initial advance increased from from 12º to 20º, and then there's ~10º vacuum advance on top of that. The brakes now function as well as they did previously and the engine runs a lot smoother. Disconnecting the vacuum advance causes a lumpier idle and the brakes start getting touchy.