If you have an engine that meets the description above? Please share your cam specs.

Thank you

 

Not that difficult with a 1000 rpm idle and decent sized cams. Mine was a 383 with a 230/245 109 lsa idling at 1000-1100. Got close to 14".

Tuned a 383 afr headed deal with a baby 224/230 113 and it was around 15-16" with a lower idle speed 800-850 ish.

Proper fuel mixture and timing can be the difference in a few inches vacuum

My low comp big head 400" turbo motor idle 12" with a 950-1000 rpm idle with a big 246/252 .640" 113.5 lsa cam. Pretty big cam

All hyd rollers to give you an idea

 

Thank you

 

232/240 @ .050 roller on a 110° LSA installed on a 106° ICL was about 14 in/hg @ 950 rpm in a 10.5:1 TPI 383 in my old TPI G20 van. I ran that setup with both a 7730 MAP TPI ECM and a LS 0411 PCM with Vortec 5.7 electronics. Just swap the vacuum booster for a hydroboost and forget about it. I did it in both my G20 and Express vans. The vacuum a/c stuff and vacuum cruise control worked just fine with a good sized vacuum canister. On the old G20 the brakes also worked well with a canister. The hydroboost just worked better than the vacuum booster ever did even with 22 in/hg from the old stock 305.

Idle timing advance can make a huge difference in the idle vacuum as well.

I have a Lunati 218/228 on a 112° LSA in my 350 Express van and it pulls about 18 in/hg @ 750 running at 30° BTDC. The 0411 and idle spark variation alont with DBW throttle body keep it sounding nearly stock at idle.

 

Not a 383 but 334 (same 3.75" stroke but in 305 block).
Crane Powermax 2050 HFT - 14" at idle 216/228 112/107 .484/.512 (1.6) (CCC QJet).
ISKY 264 Mega HFT single pattern 214/214 108/108 .480/.480 (1.6) (M4ME QJet). 15" at idle