biggest howards cam in a 350 chevy and still have vacume

I have a hard time believing the vacuum is as low as it is. Sometimes I find it helps just to walk away for a bit. I may wait until the weekend as I felt pretty frustrated with it last. I ended up getting slammed at work so I haven't had a chance to mess with it much more. The cam is installed straight up which I'm sure of, I did not however degree it in when installed. Thank you!Īs far as my dynamic compression, I am not certain, I've never figured it. Any insight or advise would be greatly appreciated. I'd really like to retain my power brakes. I have set and reset the EFI's idle control setting/throttle blades/IAC motor to their specs. Am I missing something here? If the FAST EFI throttle body/EFI system contributing to it. I'm reaching out to you guys for you opinions.

It seems everything else I could find from other people running it reported having ten to fourteen inches. I jumped on the internet looking for other people running this camshaft and their reported vacuum levels. I readjusted the valves last night, again with no improvement. It did not seem to make much if any difference in the vacuum department. I'm running about 12 degrees of initial timing and have played with it, adjusting it anywhere from about five to fifteen degrees of initial timing. I've also checked to confirm the throttle body it bolted tightly to the intake and that the intake bolts themselves are tight. I've gone back and checked to make sure all the vacuum ports on the throttle body are sealed up and removed the vacuum lines one by one, plugging them to see if I picked up any vacuum due to a downstream leak. I know it has 110 degrees of lobe separation, but still it seems to me I should have better vacuum then I do. Comp Cams advertises the camshaft as producing 12 inches of vacuum at 800 rpm and 14 at 1000 rpm on a 355ci engine. I was able to take it on its first drive last week and discovered their doesn't seem to be enough vacuum to operate the power brakes. I'm running an HEI run off of a MSD 6AL box. It has Headman 1 5/8' long tubes to a full length 2 1/2' exhaust with an X-pipe and Magnaflows.

I have an original FAST EFI system on it. Additionally, it is about 10.25:1 compression and running a Performer RMP intake and Performer RPM heads. The cam specs are at the bottom of this post. The engine is running a Comp Cams 276hr hydraulic roller camshaft with 1.5 roller rockers. I am finding I only have about 6.5-7 inches of vacuum at idle, at about 800 rpm.

Insight needed! So I have a fresh 385ci SBC stroker I built myself.

Biggest howards cam in a 350 chevy and still have vacume