I'll be testing the vacuum on my 235 next week. Can anyone tell me what to expect? The engine is running great. My mileage is good and the low rpm idle is very smooth since I converted to HEI. My new booster for the disc brakes requires at least 18 inches - that's why I'm asking. I'll be plumbing the new hard line next week also and then project will be finished. As long as I have enough vacuum
