I'm about ready to install the carb on my Performer RPM intake. I'm trying to sort out the vacuum lines.

So far, here is what I figured out:

Carb has a timed vacuum port. This should be run via a vacuum line to the vacuum advance on the distributor.

Carb has a PCV port. This should be run to the PCV valve on the valve cover.

The only other thing I see that needs a vacuum is the all-important brake booster. From what I understand it needs manifold vacuum. The problem is the bottom of the Holley DP is awfully close to the vacuum port on the back of the manifold. I will need to plumb the brake booster to that port unless I am missing something.

So, what will fit there? Is there a 90 degree fitting that will fit between the two?

There is another small vacuum port on the 4150 but I don't think it will be used for anything. The instructions say it is "manifold vacuum source for air cleaner, air pump diverter valve, or transmission modulator."

I know this has been some by some folks on the board and I am just fishing for some ideas.

 

There are fittings you can buy that are made to fit without a spacer....only problem is I bought 2 different ones and neither one fits without hitting to fuel bowl. I personally can't run a spacer with this set up and my stock hood. I plugged my manifold port and run my brake boost to the port at the rear of the carb base, the trans vac line (th350) to the front port teed off to run the vac advance. I don't run a pcv anymore I just run breathers. Sorry if this is no help but it is just what I tried and what is working for me. I believe the rear carb base port is full manifold vaccum.

 

Thanks for your help. Any suggestions are always welcome! I'm going to try something like this one: http://store.summitracing.com/partde...0&autoview=sku to see if it will work for this application.

 

Well, the edelbrock fitting was still too tall.. See pic. Looks like I'm left with using a T fitting somewhere.

 

Its just a thought, you could plug that port with a plug and drill and tap a new hole in the intake further down the intake runner away from the carb so you can put in a fitting.

 

True. I could do that..
I have a 1" carb spacer laying around here somewhere. I guess that would be another option. I'd have to check for hood clearance.

 

Good luck getting that hood to close, mine is tight with no spacer and would't close with a 3/4 inch spacer. It would close with a 1/2 inch spacer but the air cleaner lid contacts the hood.