E303, after being anal about making sure there were no vacumn leaks, valves adjusted perfectly. At idle I always got 12 in my stock lower end HCI 302.

Matt

p.s. I hate E303s, go custom. Better power, better driveability.

 

currently 8hgs with a b303 cam
eddy heads gt-40 upper and lower
b cam, 1.72's, 70mm t.b etc. 8 is really low. i cant figure out why i think the previous owner did not degree the cam . the whole setup will be changed anywayz...

 

my old combo had a b-cam and it pulled around 10-12.

i have the F-cam now and it actually pulls a tad more at idle.

 

It's actually not so much an engine project as a rules project and I was considering putting in a manifold vaccum limit. But those numbers are quite a bit lower than I expected. My stock 5.0L HO pulls about 17 in/Hg.

 

I had right at 10 with my b cam, 1.7, p heads, weiand stealth intake. and 650 dp.

 

manifold vacuum b303 cam

TO Matt,Hi I have a 302 EFI SET UP IN AN 85 LX, WITH THE B303 CAM AT IDEL I GET 13 -15 HG.
I Had to install a vacuum reserve tank from crane cams, plus installed check valve off intake manifold, plus installed a gauge to see current vacuum readings.
Now vacuum is up to 16-21hg with the reserve.
My latest thing is the install of the electric vacuum pump from stainless steel brakes,purchased thru summit racing.
Vacuum is now constant with 85 stock brake booster at 21hg, its still in series with vacuum reserve tank.
My mastercylinder is svo 1-1/8 bore with 73mm fronts and baer rear brakes.
I hope this helps ,if you have any questions ,you can call me at 561-683-6257 ask for Big mike .

 

16 at 800 RPM idle.

 

elevation plays a big key in this too.. I had 22" when I bought my car in ohio, and was down to 16" 1600 miles later in Montana..

 

My elevation is 43 feet.

 

Really hard to compare because other combo differences (heads, intake, exhaust choices, cam timing) can impact vacuum at idle. My mild exhaust restricted combo could only muster 11" at 1100 rpm. I lived with it for about 3 weeks and then ordered a custom. Back up to 18-20" at 750 rpm.

Oh - that was the E......thanks Trey.

 

Oh yeah, I have a B cam.

 

Mine had 12 in-Hg cold, and 15 in-Hg warm at idle. Stock 155,000 mile shortblock.