Converting to power brakes, where to pick up sufficient vac on an I6?

[TimberwolfFXDL]

There's no good sized ports below the throttle blades that I can see.  There's one 1/4" O.D. port that's plugged by a previous owner.

Should I drill and tap the intake?  Or am I missing a usable port somewhere?

[zieg85]

There's no good sized ports below the throttle blades that I can see.  There's one 1/4" O.D. port that's plugged by a previous owner.

Should I drill and tap the intake?  Or am I missing a usable port somewhere?

1/4" should be sufficient.  I think the standard port you need is right below the carb closest to the brake booster

[78 Chevyrado]

If the 1/4" isn't enough, put in a vacuum canister somewhere.  They are common in boneyards and easy and cheap to acquire.

[TimberwolfFXDL]

Well, I ended up finding a co worker with an 85 Tioga RV with only 55k miles.  It's got a nice 350 and th400 trans in it.  Scored it for about $500.  Plan is to pull the drivetrain and scrap the RV (or part it out), sell the th400 and reseal/paint the 350 and stick it in the stepside for now.  Should be a sufficient vacuum port on that one to pull for the brakes.

[zieg85]

Seems like an awe-full amount of work for power brakes but two each is own.  You will like the upgrade in power.  Make sure you find a larger radiator and proper SB V-8 fan shroud as you may have cooling issues if you do a lot of stop and go traffic in a hotter climate.

[TimberwolfFXDL]

haha, yeah I'm not swapping motors just to get power brakes

I have two radiators right now... one from a 90 blazer (I wanted the core support and grille, etc but the guy threw in the radiator, shroud, condensor and trans cooler on the deal), and also the one from the RV.

[zieg85]

haha, yeah I'm not swapping motors just to get power brakes

I have two radiators right now... one from a 90 blazer (I wanted the core support and grille, etc but the guy threw in the radiator, shroud, condensor and trans cooler on the deal), and also the one from the RV.

Gotcha