Rudder

All,
First off, thanks in advance for the help. I’m building an EFI’d 347 w/AFR heads, cam, TFS intake and a (small) single turbo for my ‘65. Anyway, I’m looking for what kind of vacuum readings you’re getting at idle with your engines/combo. I’m asking because I’m looking to convert the car to power brakes for safety reasons. I’m going w/a booster or a hydroboost unit, depending on what I get in replies. If you’ve noticed low vacuum what did you do to correct it?

I haven’t built the engine as of yet but my heads/cam will be Ed Curtis units. No 302 parts on this beast. LOL I know cam specs (in general) play a big part in vac readings but i'm just looking for a baseline for reference.


Again, thanks for the help.

mjr46

there is no baseline reference, as you know is all depends on the cam, most 347's have stout cams and vaccum is low.

AdderMk2

I pull 14 in/hg.

Rudder

Thanks much...looks like a booster may be in my future. I'm going to chop an 8.8 to fit in the car with some Cobra brakes so i need more psi over the fatory drum units.

Unless someone has a 9in for cheap. lol

AdderMk2

i pull 14 in/hg in my 347, WITH a full cobra brake system.