vacuum test
 

Sorry if this is such a noob question..
Where do you connect a handheld vacuum gauge to test the vacuum?
on a 85 Impala with the 305 and quadrajet

Valid question. Insert it into the vacuum system anywhere furthest from the carb.

Thanks..no specific spot or anything?

What exactly are you looking for?

I'm just trying to test the vacuum to see if I come across any problems and I need to turn the cap until I get the highest reading...since it's my first time ever doing this I didn't know if there was a "best" spot to check for vacuum

If you have a Vacuum Canister on your brake system, you probably should do an integrity test first, to make sure there are no leaks. And, a lot of people just use the Tach to get the most RPM's from the setting, then readjust the idle speed.

well i did the vacuum test, did everything i could to get the highest reading except the idle mixture screws because i need the double d socket or fitting for it..i also took a video of it on my cell phone if anybody wants to see

vacuum test (phone quality) - YouTube

if you cant watch it, the needle measures 19 to 18 in but occasionally flickers to 17...in the video i also look at the tach and you can see it dipping down to about 5-600 then back up to 8-900. which is when i think the vacuum gauge drops an inch to 17

tell me what you think
any input is GREATLY appreciated
thanks

Well, first of all it is a 305. Setting the timming with vacuum is ok, I seem to see around 800 rpm's on the tach, that too is ok. How many miles on the engine?

55k on the dash but I'm not sure if it rolled

And it unfortunately does not have the original carb on it.
The owner before me changed it from #17085*** to #17083204