Originally Posted By topside
GM and others have been using electric vacuum pumps on street cars for a long time.
On a sound 500HP engine with normal ring tension, the factory setup has worked for me.
On my Duster drag car, when it wasin the 11s & no mufflers, a pan evac worked. When I got greedy, with low-tension rings as part of the revised combo, put it in the low 10s, and added a bit of 3.5" exhaust & Bullets to meet a Db rule, the pan evac wasn't as effective, some smoke from the pipes. Changed to a regular GM electric vac pump & vented puke tank. Fixed. Sucks out of one valve cover, pulls 5" of vacuum measured at fitting on opposite valve cover.


I know of a few people running those and some like em some don't but I pull 12+ in. of vacuum cruising and around 7 idling so I'll stick to this BUT, at wot the 5" is better then the 0-2 in. of vacuum a lot probably see there...........


72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....