Carb's and boosted brakes

[HelmetHead]

I have read through many of the threads related to hooking up the vacuum assist brakes to PMO's and Webber carbs utilizing the left side intake runners or vacuum bungs provided on some carbs/manifolds. My carb's dont have vacuum ports nor do each of the 6 intake runners have a drillable bung.

I ended up drilling the left side runners for #1 and #4 cylinders on my webber non-vacuum intake and I plan to plumb both #1 and #4 to a "Y" fitting and from that into the tunnel vacuum line. I've seen the various setups utilizing all 6 cylinders and a manifold block etc, etc...is this really necessary?

My question is, do I need to use a check valve or something in each of the two lines before the "Y" to prevent vacuum sucking from alternating ports or does the check valve located on the brake booster all I need. The reason I ask is my other car only has one vacuum port tied into the carrera intake and there are no check valves other than the one on the master cylinder booster.

Your thoughts?

Oh, and I know you guys like photos so here it is

[James Brown]

I would only use one port for the brakes with a check valve. to prevent cross flow.

[KTL]

I have one of the traditional setups on my '79 and it seems to work good. The brake booster hose has a check valve on it near the intake manifold and its tapped into the #2 intake runner beneath the Webers.

My brakes seem to be well boosted because I don't find the effort noticeably different from my '87 Carrera. I don't think the brakes are underboosted because in the three years i've had the '79 racecar, I haven't found the brakes to wear me down during longer races (40 min. sprints).