So I'm going to be that guy that just asks a question rather than spending hours searching posts hoping to land the information I need.

Pops and I are In the process of putting a built 350 into a 83 Z28. First build of this depth have done plenty of motor installs over the years as that's what I do for work. First custom install though. Removing the electronically controlled qudrajet and going with edelbrock performer, also going to a vacuum/mechanical advance HEI distributor. Trying to figure what I need to do electronically as far as the computer goes, what to keep for wiring in the motor bay, if I can use the ecm in the car. Or if I need an ecm out of something older to operate the choke as that is the only part on the install that is electronically controlled. Any advice or personal experience would be excellent, or links to places this info could be found!

Thanks in advance for any and all help.
-Tiny.

 

Choke is not run by the ECM. If the car has an automatic transmission, the ECM controlls torque converter lock-up.
There are kits you can buy that lock up the TCC without the ECM. You can eliminate all the ECM wiring that comes through the passenger side fender apron and kick-panel...

 

You and I are doing something very similar. I'm putting a 1987 L98 350 out of a 9C1 Caprice into my car, and I Frankensteined a carburetor with my Uncle to "delete" the electronic emissions controls from it. I'm not experienced at all with anything out side of Quadrajet carburetors, but in principle all carburetors essentially function the same way. The "electronic" choke is really just a heating element spring metal that expands as it gets hot. As it gets hot, it opens the choke. No need for a computer, all it needs is a wire that's hot when the ignition is on.

But here's the thing... as far as what you need for the computer? Nothing. Toss it out. If you're using a non-computer controlled carburetor, and a distributor that doesn't require computer controls, then you essentially have no need for the computer whatsoever. You're going almost totally analog with maybe the exception of your distributor which will have an onboard, independent control system on it that really only regulates the spark control. As far as wiring goes, it depends on what condition your current engine bay wiring harness is in. What I did was I took the complete wiring harness out of the donor car I got the engine and transmission out of, and I'm going to use that instead of the one in my Firebird currently. Why? Because whoever owned my 'bird last absolutely destroyed the wiring harness... it's an absolute mess, and a legitimate fire hazard. The only thing I'll need to figure out is how to adapt the portions of the wiring harness that are unique to the Firebird (the flip up headlights in particular) into the other harness without hacking it up.

To add onto what T.L. said about the Torque Converter Lockup, typically the lockup wiring will have a four port connector with three wires that goes in about midway down on the driver side of the transmission... one wire will be ground, one will turn the lockup on, and the third will be the cancel. There are ways to control the lockup with a specific vacuum switch designed just for that purpose, and set it up to cancel whenever you hit the brake. You can also have it set up total caveman style by simply putting a toggle on/off switch for it as well. Turn it on when you want the converter to lock up, and then turn it off when you don't. Can't get any simpler than that.

 

There seems to be a general misunderstanding of what is "Electronic" vs. what is "Electric".
...and I do not fault anyone for not knowing the difference.

In today's world... the two terms are somewhat used interchangeably.
They really should not be...
But even ThirdGen.org uses the incorrect terminology for the "Electronics Forum".

Both the Carburetor Choke Coil/ Heater, and the Torque-Converter Clutch Solenoid are basic/ simple "Electrical" Components.
They do not need any Computer Control to function.
12v+ and 12v- is all that is needed to operate both of these Components.

 

For the guy with the 83:

LOOK AT the car. Carefully. (the wiring specifically)

Observe that there is a large connector coming through the firewall near the brake booster, with 2 halves. One half has body type things in it: headlights, horn, and so on. The other half has engine things in it: battery feeds into the cabin, gauges, ignition, starter, etc. The windshield wipers are in one of those but I can't recall which.

Obviously, you need all those things, NO MATTER WHAT motor you have. They would be the same for a 4-, 6-, or 8-cylinder engine; the same for a carb, EFI, or what; they are unrelated to any "options" the car has, such as AC, power windows, etc. In short, those 2 MUST remain, and MUST be connected to the engine, regardless of whether it's a 305 or a 350, for engine-related things to work. LEAVE THEM ALONE.

There are a few smaller harnesses here and there; notably, one for the cruise control, and one for the HVAC. Leave those aside for the moment. DON'T CUT ANYTHING.

Observe also that there is another COMPLETELY SEPARATE harness coming out of the pass side fender, right by the blower motor. Observe carefully where THOSE wires go. You will find that they connect to "sensors" (as opposed to gauge sending units), the electronic carb controls, various emissions devices such as the AIR, etc. That ENTIRE harness can be removed, intact in one piece, WITHOUT CUTTING ANYTHING. It goes through the inner fender well, through the side of the windshield cowl and into the passenger compartment, and plugs onto the ECM. You can remove THE ENTIRE THING without cutting ANYTHING, by unclipping the big plastic U-shaped clippy thing on the interior side of that pass-through, kind of behind the pass side kick panel.

I strongly suggest that you do JUST EXACTLY THAT. Remove that harness WITHOUT CUTTING ANYTHING (don't even PICK UP your dykes, let alone use them), INTACT, UNMOLESTED, and PERFECT. Remove the ECM as well. Put all that in a box and set it on your shelf.

Then when you put this hypothetical new motor in, just put the sending units and whatnot back into it just like they were in your old 305, and hook them up, just exactly as if the 305 was still there instead of an otherwise nearly identical block with a larger bore.

Don't outsmart yourself and create problems that you don't already have by "cleaning up" (which is the euphemism people use for HACKING ON) the wiring. Just don't. It isn't necessary, and all you will accomplish by "cleaning up", is making more work and expense for yourself in the long (and not so long) run.

 

Just want to echo what Sofakingdom said. When I pulled the harness out of the Caprice, I took it out in its entirety and I spent a good amount of time (including going out of the way to remove the passenger fender just to gain better access to the HVAC and computer harness) methodically removing the harnesses without cutting anything. ANYTHING. I may not be using any of those computer controls, but what I should also emphasize is that I will still be keeping literally everything that came on that harness. If it isn't being used, it can be folded up and tucked away neatly. If I need it later for some reason - say for example I decide I want to say... run a factory TPI set up or something - then I have a harness with most of the things I need to make it work and won't need to modify as much. If I don't, then if I ever decide to sell the car the next guy won't have the same problem I'm having right now with having to sort through a hacked up fire hazard that'll make me look even more incompetent than I already am lol

 

At least with Third-Gen Cars; I also remove the entire assembly through the Passenger-Side Fender.

However, I do not like to keep the original Cabin Pass-Through for this Wiring-Harness.
I instead cut-out the original Cabin Pass-Through, and weld in a new-piece of sheet-metal that can house two Bulk-Head Connectors.

I install two of the Delphi sealed Mixed-Metri-Pack 38-Terminal Bulk-Head Electrical-Connectors so that original Wiring-Harness can be split in two.
Half can stay in the Cabin, if the Engine-Compartment half needs to come out... or vice-versa.

 

thanks for the info guys! As far as cutting goes I don't cut anything on a car unless it is specifically to replace a pig tail, or repair wires no matter how good you do daylong to "clean up" you can tell a back job from a mile away. That's why I was looking for accurate information from people who have done the swap before. I do plenty of motor swaps any trans swaps, just first time going "backwards" in technology to get out of the smog era B.S.

Anyway thanks again for the information! With any luck, a few energy drinks and a straight caffeine IV drip the old girl should be bolted back up and hopefully getting the break in on the cam done by dinner time Sunday, provided the trans swap on my kids jeep goes smoothly Friday night!

Next on the list over winter will be gen 4 rear ax install for posi and slightly wider stance!