Q-jet to Edlebrock vacuum questions

[wrightjt2007]

So if you've read any of my past posts you know that I've done a complete emissions delete and swapped my bad Q-jet for an Edlebrock on my 305 5.0L V8 1983 Chevy K10 silverado. I was wondering if anyone else knows how the ported vacuum works compared to the Q-jet, what is mean is it know there are several ports on the Q-jet and only 3 on the Edlebrock. I have the distibutor vacuum advance hooked up to the port that gets vacuum when you open the throttle. And the other port with constant vacuum hooked up to a vacuum tank in the very corner of the engine bay. The truck has been running great with out the vacuum but just recently it started to dump antifreeze which im thinking it was the thermostat housing ( I just replaced it today) the hoses (also just replaced today) or the water pump itself. I plan to start it up and watch for the weeping hole to leak but haven't gotten to it yet. With the fact that I has been running great in mind, I dont really think I need to add a whole lot of the vacuum line back maybe a few. I would just like to know which vacuum line are absolutely to add back. Also, do I need to hook the vacuum back up to the Tip In Vac Switch and the Trans Torque converter vacuum thing (both are bolted to the fire wall if what i said was confusing). And what do they do???

Please read all of this if you can, I know its a lot of words.
Here are pics of what I've deleted

 

[xm20k]

Manifold vac for brake booster and pcv valve. line to distributor and a line for the modulator on the transmission if it has one and is stock i.e. not a manual VB and still shifts itself.

 

[wrightjt2007]

Manifold vac for brake booster and pcv valve. line to distributor and a line for the modulator on the transmission if it has one and is stock i.e. not a manual VB and still shifts itself.

Ok I was following you until modulator, I didnt understand the rest after that

 

[xm20k]

Doubt you have a built trans, so it most likely has a vacuum modulator that adjusts shift points based on engine load via manifold vacuum.

Some people run without it but it may cause the shifts to be say too early like pulling a hill and it suddenly jumps to 3rd and acts as if it has no power. Until you mash the gas and make it kick down via the cable. The modulator would have told it to stay in second.

Pardon Our Interruption

 

[Matt69olds]

More than likely, you’re going to have to spend some time playing around with the advance curve of the distributor. Now that all the factory emissions crap is gone, the factory tune up specs are useless. The total timing will be way too high, and the advance will max out at way too high of rpm. Combine that with way too much vacuum advance, it’s going to take some experimenting to get it right.

Personally, I prefer my vacuum advance on manifold vacuum. Some people prefer ported. Try it both ways. The important thing, give the engine what it wants, not what you think it needs.

Read this:

Timing & Vacuum Advance 101 -good article by GM engineer

www.460ford.com

As for the vacuum switch for the TCC, personally I’d yank all that stuff out and wire the TCC thru a time delay relay triggered by the 3rd or 4th gear (depending on what transmission you have) pressure switch and a cruise control brake switch.

That’s how I have mine set up. As soon as the transmission shifts to 4th gear, the 4th gear pressure switch ground the relay. Ten seconds later, the converter locks. Touch the brakes, the brake switch removes power from the solenoid, instantly releasing the converter. Let up on the brake, assuming the trans is still in 4th gear after 10 seconds the converter will automatically lock again. It’s about as close to a factory feeling lockup strategy you can get without a computer.

 

[xm20k]

Forgot 83 came with a 350, 350c, 700r4, or a th400 so depends on what trans is in it.

 

[wrightjt2007]

First off I want to thank you for all of that information. So basically what I got form that was I need to hook my vacuum advance to the manifold vacuum. Yes I have a rebuilt 700r4 (its the stock transmission). Basically this truck was running great but then it started leaking antifreeze and I started going down a rabbit hole as to what all I've messed up by removing all of the vacuum. Also, (vacuum advance set aside) what do I do with primary and secondary thermal vacuum switches that sits on and next to the thermostat housing. Right now every port on these are capped off. Do I need them or can I get rid of them and make my engine look a little better

 

[wrightjt2007]

More than likely, you’re going to have to spend some time playing around with the advance curve of the distributor. Now that all the factory emissions crap is gone, the factory tune up specs are useless. The total timing will be way too high, and the advance will max out at way too high of rpm. Combine that with way too much vacuum advance, it’s going to take some experimenting to get it right.

Personally, I prefer my vacuum advance on manifold vacuum. Some people prefer ported. Try it both ways. The important thing, give the engine what it wants, not what you think it needs.

Read this:

Timing & Vacuum Advance 101 -good article by GM engineer

www.460ford.com

As for the vacuum switch for the TCC, personally I’d yank all that stuff out and wire the TCC thru a time delay relay triggered by the 3rd or 4th gear (depending on what transmission you have) pressure switch and a cruise control brake switch.

That’s how I have mine set up. As soon as the transmission shifts to 4th gear, the 4th gear pressure switch ground the relay. Ten seconds later, the converter locks. Touch the brakes, the brake switch removes power from the solenoid, instantly releasing the converter. Let up on the brake, assuming the trans is still in 4th gear after 10 seconds the converter will automatically lock again. It’s about as close to a factory feeling lockup strategy you can get without a computer.

how do i rigg the tcc to the 3rd or 4th gear.

 

[wrightjt2007]

ok so in response to myself, hear me out... i asked copilot ai and it gave me an entire set up. im going to get my truck back on the road and test out this setup and see how it goes. might make a new thread on how trustworthy is ai for squarebodys.

 

[Matt69olds]

how do i rigg the tcc to the 3rd or 4th gear.

HOT ROD Rescue: Lockup a 700-R4 Torque Converter Without a Computer

How to Lockup a 700R4 Torque Converter Clutch Without a Computer Using a Manual Switch and ISO Relay.

www.hotrod.com

The time delay relay I bought from Amazon. It was around 15 bucks. The problem with using a standard relay is the converter locks immediately after the 3-4 gear change. That tends to really drag the engine down.