: '81 Coupe DeVille engine swap 305!!!



oldlaclover
05-20-11, 06:07 PM
So I have been working on this car off and on for about five years now, been through 2 different engines and now have been handed a rebuilt 305 out of a '86 caprice. I want to know what length of drive line do i need for my coupe and are there any donor cars that would make it cost efficient?

sven914
05-20-11, 06:38 PM
If you are using the 305's THM 700 Transmission, then get a drive-shaft from a '91 or newer Brougham. They all had Chevrolet motors.

If you are keeping the factory transmission, then the drive-shaft length should not change, but you need to get an adapter for the bell housing.

cadillac kevin
05-20-11, 11:18 PM
sven, so would one off a 93-96 fwb work? I thought those cars had a different wheelbase than the 78-92 cars (although I could be wrong).

sven914
05-21-11, 12:25 AM
They just look larger because of the bubbliness.

oldlaclover
05-21-11, 05:57 AM
Thanks for the info I'll check up on it tomorrow and see what transmission i have attached to the motor.

oldlaclover
05-28-11, 07:15 PM
So i went out to try and rip down this headliner only to be met by a seized up passenger side door. Does anybody have any suggestions on how to go about getting this door open?

Stingroo
05-28-11, 09:18 PM
They just look larger because of the bubbliness.

Actually the 93-96 cars ARE larger, but it's because of overhang. :p

sven914
05-28-11, 10:08 PM
^Bubbliness...

brougham
05-28-11, 10:48 PM
Your driveshaft length depends on what rear axle it has too. It's not just the transmission.

oldlaclover
06-11-11, 08:04 PM
So Just got around to going out and seeing what the deal was under the car, and it looks like i have a th-350 or 400 going on and need advice as to what i should do about my drive shaft. Are there any other cars that used the same length drive shafts with the th-350 and 305?

jayoldschool
06-11-11, 09:07 PM
You have either a TH400 (if you have a gas V8), or a TH200-4R (if you have a diesel or a Buick V6).

oldlaclover
06-11-11, 10:06 PM
So if it's the th400, are there any cars drive shafts that are compatible between the caddy and the chevy motor?

csbuckn
06-11-11, 10:36 PM
If it were a 400, why not keep it? Your rear gears should be pretty high so you wont hurt as bad in gas mileage. Then you would have a strong tranny and wont have to mess with the driveshaft. Thats just another option.

oldlaclover
06-12-11, 06:54 AM
So my drive shaft should be okay and i won't have to modify it at all? I have only heard that i will need to get one cut or extended.

jayoldschool
06-12-11, 02:12 PM
Driveshaft will work perfectly if you keep the trans.

oldlaclover
06-12-11, 10:28 PM
So I just wanted to let you know that I still have the original drive shaft from the DeVille. Whenever i have taken a look in comparison it looks a little bit shorter than it should be. If it's okay to use this i will by all means. I just wanted to make sure we were talking about the the driveline on the deville and not the fleetwood.

sven914
06-12-11, 11:05 PM
They're really the same car, so it wouldn't have mattered either way.

brougham
06-13-11, 12:40 AM
It does matter when you're mismatching parts. If you've kept the original transmission and its mounted in the same place it's a non issue like Jay said. If you've changed the transmission the driveshaft length needs to change by the same amount as the transmission length.

oldlaclover
06-24-11, 02:45 PM
anybody know where i can get the wiring diagram for chevy's and the caddy? Trying to convert all this wiring over to the 305, and i'm keeping the carb from the chevy.

csbuckn
06-24-11, 02:52 PM
What wires do you need to know about?

oldlaclover
06-24-11, 03:14 PM
Pretty much the basic engine wiring: the starter, the lights, alternator etc. vacuum hoses and what not

csbuckn
06-24-11, 09:54 PM
The lights should still work. For the distributor, you will need to find the coil wire that was going to the 368 distributor and hook it up to the sbc dizzy. Use the same wires from the 368 starter and run them to the new starter, you may have to extend them a little. The alternator should plug right with no modification if I'm not mistaken.

oldlaclover
09-09-11, 01:16 AM
So while looking at this engine it seems that I'm missing the environmental connection and that's where a few wires from the dizzy should be going. Is there a way to re-wire it (the dizzy ) into another harness?

csbuckn
09-09-11, 01:38 AM
The distributer just needs a 12v switched power wire going to it. Could be as simple as running a fused power wire to a kill switch, then to the dizzy.

oldlaclover
09-09-11, 01:59 AM
I'm just gonna let you know I'm not the best with electrical stuff. But how would I go about making. A fuseable. Link wire?

csbuckn
09-09-11, 03:36 AM
What motor is in the car right now? The 368 has a power wire going to the dizzy and you can test it with a test light. With the ignition off, that wire should have no power. With the ignition on, that same wire should have power. If the wire test correctly, that will be the wire you hook into the dizzy in the IGN spot to give it power. The proper way to test the wire would include making sure it has twelve volts but you should be okay.

camarotim
09-09-11, 08:38 AM
I just did an engine swap in an 83 de Ville and the power wire for the distributor was pink with a white single connector on it. It's a little heavier gauge (thicker) than the other wires running to the engine. If I remember correctly all of the older GM cars around this vintage used the pink color for the power wire to the distributor. Once you find the wire it plugs into the "bat" slot on the distributor cap.

oldlaclover
09-09-11, 02:09 PM
It has the 305 in it. It came out of a 86 caprice. I have wires going to the starter and although. But I'm having trouble trying to figure out what to do with the dizzy. I looked at my wires coming from the left side bulkhead and I have a rouge tan wiRe that's alongside the other wires that run to the starter. Could that be the wire that goes to the dizzy?

csbuckn
09-09-11, 02:22 PM
That is a coil wire also. You can tap into that in a pinch but you should have a separate coil wire for the dizzy. Its thicker than most of the wires coming from the bulkhead, mine was pink also. I think you are thinking too hard about the coil wire, all you have to do is get constant 12 volts to the dizzy when the ignition is on. Some people will tap into the wiper motor power wire.