What to do what to do?

[Telecasterjoey]

So here's my situation. I've got a tired 305 in my truck and I wanna spruce it up. I'd like to just get it running well enough to put the truck on the road for now. most of my vacuum hoses are either missing or hooked up wrong. I'd like to delete the emissions stuff and just run the bare minimum for vac hoses. So question 1: where would I hook up the vacuum hose that goes to the distributer? (pic 1 shows the hose on the distributor) and where does the vacuum suction come from? it says in my manual that the stock breather has a vacuum motor, but when I look at motors on the forum most people don't use the stock breather.
Also I read that the transmission needs a vacuum line to shift?
I have a few pics of sensors or vacuum switches that I'm lost as to what they do!

And another option I have is swapping the motor for a strong running 350 out of a 72 buick skylark, but I was told by the guy selling it that it wont fit. Does anyone know if it will? I'd assume a gm 350 would just bolt right in. I know you guys will have the answers though!

So what are your thoughts, if the buick 350 fits should i do it? or just get my 305 running?

all input is appreciated!

[benoit454]

ok that vac. switch on the firewall is the "tip-in" switch for the torque convertor lockup. If you have a 700r4 or a th350c. if you have a 700 you do not have a modulator at all so it does not need vac. to change gears. None do really it just takes a long time to shift but it's not the point. Now if it's a th350c you do need it. It goes down to the PS of the trans at the end. The one on the firewall should stay. I forget exactly what all it does, but the vac to dist usually goes to the carb, it can be hooked to a ported vac. which means no vac. is coming or pulling at idle, but once you get on the gas it does. It can also be hooked to a constant or full vac. port which has vac. at all times, much like the intake does right in front of the dist. The metal thing that sticks up in the pic with lines, that's a direct full vac. port. The trans. modulator if you have one should have full vac.

As for the rest if you don't have emissions testing then take it out. Put caps on the carb where you remove the lines.

A quick and easy way to know if it's ported or full is to pop the line off withg it running, and put your finger over it to see if it's sucking, but then again if it is the idle will raise on the motor. If it does not or doesn't suck air it's a timed or ported vac.

Anything else you want to know just ask or post pics. I've de-emissioned a few of these trucks.

oh forgot to mention one of them is the tip in switch the other I think is for a/c or something. I can't remember now we had them both on dad's 84 and I removed them both. You should find out which ones has wires going to the trans. and check that iout as well as maybe somebody else to chime on what it does and what the other goes to before you remove them.

Meanwhile I'll see if I can find my post on here about them where they told me what they were.

[Telecasterjoey]

Hey thanks so much! I know the tranny is the 350 so i'll leave that switch!, The Vac port coming out of the intake definitely goes to the transmission, So I'm Guessing I can pull off all the hoses and run the distributer to the carb. Do you know what inlet i'd put the distributer hose into on the carb? Also my charcoal canister has a hose running to the carb should I leave that hose or should I delete the canister and plug that hole on the carb?

thanks so much sorry for all the questions!

[benoit454]

here's a link to my thread about the switches...

http://67-72chevytrucks.com/vboard/s...d.php?t=279479

As for the charcoal can, alot of ppl say not to remove it, but I have, you just plug the port at the carb and leave the line going to the can from the frame/tank open or put a breather cap on it, it's the vent for the tank and needs to vent.

As for the dist. it's either one, timed or full, some work good with timed, some work better with full. All I can say it hook it to a small port and not a big one.

Most of the big ones stay, one goes to the brake booster behind the master cylinder, it stays, there should also be a big one that goes to the pcv in the valve cover it stays too.

I would start it up now and pull the line off the dist. and see if it has vac. at idle, if so then hook it to a full vac. port, if not then hook it to a port that doesn't pull vac. at idle.

[Telecasterjoey]

I'd start the truck up but I'll have to put the rad back on and fill it with fluids. That may be my project tomorrow lol. One more question! where does the vac line on the brake booster run to? And what do you use for capping off the inlets? are the caps easy to find at an auto parts store?

[MTCK]

Should be a hard line to the intake back of the carb for the brake booster. In your first pic the hard line that runs right past the distributor and down the back of the motor is for your transmission modulator. There is likely a thermal switch on top of your intake that provides your distributor with full vacuum when cold and ported once warmed up. The canister can (and should) get full vacuum. PCV should get vacuum from a large port on the front of the carb. Other things that might need vacuum are your hvac switch I'd you have a/c and heat riser in your air intake that helps your motor warm up and run better in the cold. Not sure if I'm forgetting anything, it's kinda late. Napa should have new vacuum hose, tees and plugs.
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[piecesparts]

When I cleaned out my engine compartment, I ran the distributor to the front of the carb and I ran one (1) hose from the intake manifold (behind the carb to a point on the firewall to a splitter to allow for things like the vacuum controls on the heater. The brake booster mounts to the back of the carb. In my state the temissions is not serious, so I took the canister out completely and put a filter on the line from the tank and mounted it under the radiator core support (out of sight). There are different types of switches for a lock up converter and you can use one of them to eliminate the vacuum connection or move it to the same place that the one line from the intake goes to (out of sight)

[Telecasterjoey]

Hey thanks guys I think I figured it out now. Does anyone know if the buick motor will fit?

[MTCK]

I don't think the buick motor will fit.

[Your41Plague12]

Any BOP (Buick, Oldsmobile, or Pontiac) motor will require fabrication of the motor mounts to make it fit, as well as the correct transmission. They may sell an adapter, but I've never seen one.

[benoit454]

you don't need a rad to let it run for a few minutes. You don't want to drive it but I've ran them before without anything in the block or no water pump, or no water in the whole system with the rad out.

As for the plugs they are called vacuum caps they should have them at any parts store,

OR,

do it the ghetto way and cut a piece of hose that fits that nipple good, about an inch or 2 long and find a bolt or screw that fits tight in the end of it. It works LOL.

The power booster could be a soft rubber line too, you can run it to the intake or the large nipple in front or back of the carb, most of the time it's the back of the carb. Some guys run it up front, but I save that for pcv, others run it straight into that intake port.

[Telecasterjoey]

i guess i'll ditch the buick motor idea! thanks guys! i've got one more vac port i'm not sure of its right beside the thermostat housing and it screws into the intake manifold and has 2 hoses coming off it. should i plug the hoses or delete the fitting all together?

Its in this pic on the top left. under the heater hose inlet and above the thermostat housing.

Thanks again

[Telecasterjoey]

dunno why the pic isn't working.

[benoit454]

I got rid of them all together. it's a switch that has like one source of vac. going to it and when it gets to a certain temp it opens and let's vac. go to the other things.

Just make sure they don't go to the vac. switches on the firewal lif you are going to keep them. I just unhooked the lines from them on the intake and left them in place but you can completely unbolt them and get some pipe plugs to go in them or change the thermostat housing/water neck to a reg. one without the ports.