Join Date: Jun 2005. I also used the stock manifold port for my modulator line. I am not sure about the port under the throttle blade, I know that on the Holley there should be a 10-32 set screw above the air bleed screw on the primary metering block. The little capped off one is sometimes used for vac accessorizes like vac cruze control or with some cars vac headlights etc. Thanks for any help. Vacuum modulator transmission vacuum line to car rental. I have an Edelbrock performer RPM and it does have the large vacuum port on the back and that's where my transmission line used to go but the Holley carb is in the way of that now. Join Date: Nov 2015.
You can search it to see a picture and infomation on it. My guess is that is would be a vacuum modulator for the transmission, but I cannot find any place where it would go on the transmission. If you run that rubber line down to the the vac modulator on the trans, it will collapse and not give you correct shift points. What happens to this now with the LS in?
The other valve cover will have the pcv valve, which should be hooked to the big port on the back of the carb. Secondly, most "experts" suggest using manifold vacuum (under the blades) for distributor advance rather than "ported" vacuum. Join Date: Sep 2007. TH350 Vacuum Modulator Line. Re: Where to hook up vac lines on new carb. Can I just do it this way with a T hooked up to the big port on the back of the carb? You guys got it all backwards! Description: Powerglide. 79 C10 LS swap - What do I do to the vacuum line to the trans. Are you running an air cleaner spacer? Shafer's Classic Reproductions - Transmission Vacuum Lines.
Is it even supposed to be down there? "I ain't nobody, dork. Last edited by 72 Super; 06-21-2016 at 08:33 PM. Is it OK to put a T on the back so the shift modulator and PCV share the big back port?
Location: Fort Wayne, Indiana, USA. On my 72 I have a 350 with a 750 Holley doubler pumper with a Victor Jr. Intake which does not have a location to use a Vaccum fitting. Can it hook to the carb or doe it have to go to intake manifold? I do have my back and advance hooked up to manifold vacuum under the throttle blades, so Is it OK to have the PCV and the transmission modulator both running to a T off the back of the carb? No pcv and two breathers makes for a crankcase pressure problem and possible oil leaks. Vacuum modulator transmission vacuum line to carb ratio. Look at the documentation that came with your carb. I ve read where if the line isn t connected that it wears on the transmission.
I need to find a replacement line for this restoration project. It's my first Holley so correct me if I'm wrong on the vacuum advance being plugged in UNDER the throttle blades on the front of the carb too please. I'm hooking up all the vacuum lines and noticed I don't have a spot to plug the vacuum line that comes out of the valve cover into my carb. I found an extended set screw and drilled it for a vacuum fitting. Vac modulator wants manifold vac. There are a few good explanations available on the internet. Description: Turbo 350 modulator line.
72 Cheyenne Super (Purchased new by my parents in August of 71) Black and White. The big port on the back is being used by my th400 shift module, and I have the vacuum advance in the distributor hooked up to the small port under the throttle blades in front of the carb. Location: Hyattsville, Maryland. It should show you where to hook up the valve-cover/pcv hose. That line is how the transmission knows how much load is on the engine, and how it decides when and how to shift. Location: Whidbey Island, Washington. Description: V8 4 bbl. The big port on the carb is for the pcv from one valve cover.
Location: Davisburg, Michigan. The other valve cover has a breather on it. I have a 2 speed dynaflow. It's the same size as the transmission shift modulator so I can't use one of the small ports. Either a manifold port on the carb or hooked to a vacuum tree on the intake. It's whay there is a hard line running down there from the factory. Elderbrock 8096 it's available from summit, kegs, Amazon etc. Deluxe Side Markers.
Description: Turbo 350. Stockish motors run on either one. Does it have s threaded port in the rear where you can add a vaccum port? If so, it has a large hose nipple that will run to one of your valve covers. The one on the back of the intake goes to the brake booster the one big one on the carb goes to the trans the one little one the right of the carb goes to the dizzy the other little one is usually capped off. Run which ever one your motor likes. Owner installed options: Front Sway Bar. If OTOH you are keeping the Turbo 350 or 400 that you have, you need to hook it up and supply it with manifold vacuum. I know this is a little different than your set up, just giving you an idea. If it can go to the carb does it need to be on full vacuum or timed vacuum? I don't have power brakes or anything else to hook up, but the PCV from the valve cover has nowhere to go now.
Usually a big cam motor needs manifold vac. The manifold vac port and the ported port are for your vac advance. So I just got a new Holley 650 double pumper and it's almost 100% installed. The Rebuild of Creeping Death after the wreck. 06-23-2016, 02:45 PM||# 17|.