Replacing all vacuum lines

I thought I'd replace all my "highly experienced" vacuum lines with some new silicone. I was noodling around to find sizes and I'm pretty confused. Steve83 seems to imply that all of the hoses can be replaced with 5mm ID in an old post. Is that true? I'm only keeping the speed control and HVAC on vacuum; everything else is handled by the Pro-Flo.

Thanks
Chad

5mm seems awful big.  That's almost 1/4".

Ya, I thought so too. I just reread the post that Steve83 had and it said ~3mm. My bad! Does 3mm sound right? Is it the same for all of the vacuum lines?

3mm is very close to 1/8". So, yes much closer to what's there.
If you wonder about fit why not get a stub of a couple of different sizes and try them?
Then decide how many feet of each you need, and add a foot or two.

1mm =.039" x 3 = .117" compared to .125- 1/8"
.008" difference is two sheets of paper thick.

I definitely have more than one size of vacuum line on my truck.

I'll measure the outlets with calipers and see if I can get a relative idea.

thats the best way to do it.

I tried looking up sizes but there is just no real record and the only way is to measure what you have to know what size you need.

Im personally trying to find universal vacuum hose with colored stripes on them.  Everything I keep finding is geared towards GM with some geared towards Ford but Ford from the late 60s early 70s more so than 80s.

I have planned similar to what you are doing, I am going to run all new vacuum lines and keep the originals and box them up and put into storage.  I want to get rid of all the emission systems as well as the vacuum lines for it and all those plastic vacuum tubes and replace it all with just plain vacuum hose.