307 to 403 Olds swap...info please?

[81X11]

I would advise you to not bother with removing the CCC wiring from behind the dash, at least for now. What you want to remove is the CCC harness from under the hood. It's one big harness that's separate from all the other wiring. This harness goes through a rubber grommet in the firewall under the AC module. You can unplug the ECM from behind the passenger side kick panel and remove harness by removing the grommet from the firewall and pulling it all through the firewall into the car. You'll then need to plug up the hole where the grommet was. I just used a spare old grommet.

Note the grommet is secured by 2 bolts that require some effort to reach and remove. You will have to remove some bolts from the outside passenger side plasic wheel well and pry it out of your way to get to one of the bolts.

The CCC wiring has nothing to do with any of the gauges BUT the speedo does have a speed sensor that sends a signal to the 'speed buffer' which will still be needed for cruise control. Concentrate on removing the CCC harness first, then I can tell you what you need to do to retain your cruise function.

Thanks, and no I do not plan to remove the dash harness, just the underhood wiring speghetti.

Let me ask, is it not possible to cut the wiring under the hood near the a/c evap box and pull what's left from inside the car? Is the grommet attached to the harness itself, or do the wires just run through it? I'd like to retain the grommet and run the wire for the transmission through it. I'm installing a Painless kit for the lockup.

As for removing the underhood harness, I just wanted to make sure my temp, oil, and battery gauges would still work with it removed. Thanks for answering that question!

-Mike

 

[81X11]

Oh and sorry for the 10,000 questions, but just thought of two more.

I removed the AIR smog system of course, the 71 Olds heads didn't have the tubes anyway even if I'd wanted to keep it, but the metal line from the cat converter for this is still running up into the engine compartment. I'm going to replace the exhaust in a few months when money allows. For now, I want to cut that line at the coverter and plug it. What do you suggest doing it with, a bolt an a clamp down next to the converter? I don't have access to a welder, but while the car is at my friends shop and I have it on a lift, I'd like to take this off and block it for now. Ideas?

Also, can I remove the purge cannister from in front of the passenger side wheel-well, or should I retain that? I actually have it connected right now, but if it's not needed, I'll take it out and block the connections to and from it off.

Since the car is no longer original, I want it to be as clean and clutter-free under the hood as possible, but don't want to remove something I shouldn't.

Thanks again ALL!!

-Mike

 

[DoubleV]

1) Grommet; The CCC harness that goes through the grommet is a pretty tight fit but isn't attached to it per se. If you do not want to remove the CCC harness intact, your can just leave the grommet bolted to the firewall, cut the wires, and then pull the one half out from under the hood and the inside half out from inside the car.

You will then want to plug the hole in the grommet so rain and road noise won't get in. IMO, I wouldn't plug the hole with anything just yet because you may want to run some wires out that grommet. Personally, I'm running my electric choke wire and transmission lockup wires through the grommet as I'm utilising the stock under dash CCC wiring harness ( which is already hooked up to everything properly ) because all the connections used for those are right there by the grommet. Nice and clean...

2) AIR tube; cut it at the cat and just crimp it shut. That would work fine as a temporary fix.

3) Cannister; Technically you could remove it, but IMO, the best thing to do is eliminate all the rats nest of lines/hoses going to/from the carb but leave the cannister itself with the one line coming from the gas tank so the tank can still vent.

For more detail about the ECM wiring, if you can, take some pics of the CCC wiring and connectors under the glovebox area and passenger side kick panel area ( which is where the grommet is ). I will tell you how to do what you want to do without resorting to any butchery.

 

[81X11]

Thanks very much DoubleV! Will reach out when I get to this point.

-Mike

 

[81X11]

The 350 is RUNNING! And running really WELL! Woo-Hoo, at long last!

Now I have to figure out how to ground the a/c so the compressor will engage. It's charged, but with no computer it's not coming on. Have not figured that out yet and will have to look around the forums for the how-to.

Also have to sort out the cruise control and the lockup on the transmission. I'm going to drive the car home from the shop in 3rd gear tonight so as not to damage the trans. The TV cable adjustment seems to be right, it shifts fine. I'm going to order a Painless Wiring lockup kit for it, but that will be in about two weeks....next pay period. Ha! You know how it goes.

So for now I'll see if I can sort out the a/c and cruise control. I still have not figured out how to attach the cruise linkage to the new carb, and then I have to ground the wire under the dash for that. I have the instructions to do that, seems easy.

Also planning to totally remove the ECM wiring from under the hood, and do a BIG clean-up and detail. Plus I have to cut the line off the Cat Converter that is still sticking into the engine bay for my no-longer-there A.I.R. system.

ANYWAY I'm just glad it's finally running and running well. Will have some fun playing with it this weekend.

-Mike

 

[81X11]

The local speed shop gave me the name of a guy that works at Ammco Transmissions down on Burnet Rd in Austin. Said he's the "go-to" guy for all the local hot-rodders. Just called him, seems like a really good guy, and he has the transmission lockup lit in stock, and quoted me a VERY fair price to install it. It's a TCI kit, not the Painless kit, but he says it works fine.

Will be dropping the car off for that next weekend. This weekend is for cleaning and detailing, and tweaking it all. 😀

Pics to follow!

-Mike

 

[jmt455]

Glad to hear it's running!

 

[DoubleV]

It's a TCI kit, not the Painless kit, but he says it works fine.

Just make sure this guy installs it in such a way where it will unlock when you put your foot on the brake. The switch behind your brake pedal and wiring is already there! Run that factory purple wire ( pin P on that big black connector under the glove box area ) to the vacuum switch. Route the wire out the CCC grommet.

If he just taps into a different 12v source to the vacuum switch then it won't unlock when you hit the brakes and that's just hackey and not right!

As for attaching the cruise arm to an Edelbrock carb I could'nt help you there. This is one of the reasons you should've gone with a Qjet! :wink:

To get the AC going isn't hard but it's totally different then what I had to do to mine since VIN 9 AC's were set up completely different for some reason. You should get an elecrical chassis service manual specifically for your car and it'll show you everything you need to know ( in color too! ).

Glad it's running good.

P.S. You don't have to drive it in 3rd gear just because you don't have lockup. Just drive it in OD just like you always did before. The only difference is it won't lock up in 4th but during low speed stop and go driving, the ECM never locked the converter anyhow so....

 

[81X11]

SO I tinkered with it all weekend. Still have lots of tweaking to do.

- Have not figured out the proper timing yet. Set it like the 307 and it idles really rough and starts hard. Will have to Google the proper timing for the 350.

- Temp gauge is dead now, worked with the 307. The hole in the Edelbrock intake is larger than the stock 307 intake. I bought an adaptor at Napa, and it's bolted in, but still getting no reading. Either the sender is bad, or the adaptor raised the sensor up too high to get a good reading....?

- I had to install a dropped-base aftermarket air cleaner to close the hood. Put my Rocket 350 decal on it. Looks ok.

- Still have to sort the huge wiring mess out. Have not removed the ECM harness under the hood yet, but really want to do that. Stole power from that harness to run the electric choke, and once removed will have to find a new power source. Also it looks like the plug for the disributor is tied into this wiring (?). I have it all bunched up near the evap box near the engine, and it's such a jumbled mess it's hard to tell what goes where. I did install a vaccum-style distributor but did not mod any wires yet. I REALLY wish I'd pulled the wiring before dropping in the engine, but original plan was to keep the computer. Now I have 10,000 unplugged wires. Argh.

- Plugged off the PCV port on the carb and installed chrome vent caps on the chrome valve covers. They have the caps with the port for a hose and inline PCV, but don't think I need it. Thoughts?

- Still have not sorted out how the a/c is supposed to be wired to work.

- Still need to figure out how to hook the cruise control to the new carb.

Will sort out the a/c and cruise once the wiring is cleaned up and the car is running right.

Such fun. Car IS home at least.

-Mike

 

[81X11]

This was the donor car for my "new" '71 350, and belongs to a local club member named Terrence.

After all the work put in to it (a totally BUILT 403 engine, something like 400hp), it was home about 2 days, and after a day of fine tuning, it was put away for the night and Terrence took his wife to dinner.

Someone broke into his house, got the keys took the car for a joy ride, parked it in a field and burnt it to the ground afterwards. 😢

The new engine drivetrain survived and is now looking for a new home in another Cutlass or GM product. I got a call from Neill, the guy that built the new 403 put the engine in the '71, and he said Terrence is just beside himself.

Really Sad Stuff!

-Mike