Power brake vacuum source question:

[fryer1979]

I almost have all of the parts gathered up to do my power disc brake conversion on my 65. I've read through all of the conversion thread a couple times, and have been able to figure my way through all of the questions I have had about which parts to use (thanks for that awesome resource by the way!). I have all come down to one question, and it is really more of a request for suggestions than anything else.....what are you guys using for your vacuum assist source? You know, the vacuum line for the booster, how are you guys running inline 6's hooking this up? I have a few ideas, but would like to hear from others before I go forward and inadvertantly mess something up. Thanks a lot!

[k1rodeoboater]

Im going to try to tap off of the PCV hose. When I checked the vacuum gauge it read 19Lbs, and IIRC a booster needs 18lbs to function
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[61_FL_Apache]

This was the best pic I could find of my 65. you can see the line going to the PCV valve. At one point this was completely plugged up. I found another port on the base of the front of the carb too. I would think the vacuum pull was the same.

[jocko]

appropriate vac source would be from the carb base plate - i.e. the one Apache mentions on a 6 or the one that points aft toward the distrib on a v8. I would not use the pcv valve as a source as it would tend to be oily air and could gum up the booster when the check valve is open - and the factory never used a pcv valve as a source that i am aware of. The key is that it is a full time vac signal rather than a part time one - i.e. full vac available at idle (like both pcv and carb base plate are - but the carb plate should be a "clean" source). Not saying the pcv valve won't work, but the fact that the fact that the factory didn't do it that way seems reason enough to me to not do it. My 2 cents only.

[fryer1979]

Thanks guys. I'll have to look again and see if I can find that port on the carb base plate. On a V8 I wouldn't have any question, but I didn't see a port on my I6 when I first looked and didn't like the idea of using the PCV line because of the oil issue.

[k1rodeoboater]

What sort of air cleaner are you using to clear the booster? My stock doesn't clear it unfortunately.
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[fryer1979]

Honestly, I hadn't even given any thought to an air cleaner clearance issue. Guess I will just put it all together and see where it leaves me. I'll be swapping to a V8 soon , so the fix would only be temporary anyway.
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