87 Limited V8 becomes Turbo V6

[57loboy]

I plan to transplant the entire drivetrain from my rusty 87 Limited Turbo into my 87 Limited w/V8 as it has a far better body. I realize that much of this swap will be plug-and-play, however I have a few questions since there are some small electrical differences between the two cars. Specifically:

1) The Turbo car has digital dash and the V8 doesn't. What harnesses do I need to bring over for the digital dash to work in the V8 car? I will ultimately be going to a gnx-style dash, but not right away. I know the fuel senders are different and the engine harness includes the Hobbs switch...Anything else? Is the harness to the rear for the pump different? I'll be hotwiring the pump in the new car.

2) The V8 car has a few options the Turbo doesn't and vice versa - I believe the core harnesses for the interior are the same, but wanted to check to see if anyone knew otherwise. Turbo has CF5, factory theft deterrent, lighted pass vanity mirror and power trunk, V8 doesn't. V8 has power drivers seat and cornering lights, Turbo doesn't. All else is the same. Thoughts?

I will of course be swapping the rear end, steering box, springs and swaybars too...

Thanks!

 

[Brer Rabbit]

Might have suspension issues

My hybrid 87 cutlass was originally a 307 car and sits a lil to high in the front with the v8 springs. Might have to replace or cut a lil off the springs.

 

[57loboy]

Good point, I'll be sure to keep the front springs. The Turbo will get stripped bare once the swap is complete...

 

[Turbo1dr]

The fuel lines on the frame will need to be swapped also.
The turn signal switch is different if you have cornering lamps.
The under dash harness is different.


Just swap the entire wiring from the TR and then try to get the other "extra" options working? That way everything will work fine with the turbo engine and not pieced together like a rats nest.

 

[57loboy]

Fuel lines - check. Will replace all of them with new ones.
Cornering lamps - V8 currently has them, don't plan to keep them so I was going to keep the column intact and replace the fenders whenever I decide to repaint the car. As the body is in really good shape, it'll be a while.
Under dash harness - my plan is to remove the all the harnesses for the rear of car (fuel pump), dash and engine and swap in the Turbo ones. The rest of the cars are the same and these harnesses should be plug and play based on my experience with swapping engines in Firebirds/Camaros eons ago...

I appreciate the insights/advice - many thanks!

 

[Turbo Loyd]

Put a TR drive train in a 86 Limited that came with a 307 this summer myself

I needed to swap out the heater box as the limited AC box extended into the engine bay 2 inches deeper and would have made changing the #6 plug a PITA. Of course to change out the engine wiring harness the passenger fender and inner fender have to come out anyway, to access the wiring harness seal through the firewall.

Since the dash was out, to change the heater/AC box, I found the harness mounted behind the dash was slightly different so changed it out as well. That harness includes the fuse block, plus the plugs that go into switches into the steering column and connectors to the dash as well. Having the dash out made this relatively easy, but did take quite awhile.

All the power options just plug into the fuze block and are in a seperate harness that was not affected by swaping out the main harness.

The chassis wiring harness under the hood is one half of the C100 (main bulkhead) connector that is mounted on the back of the fuse block. So changing out the engine wiring harness will not affect the chassis wiring as well.

I changed out the harness from connector C209 the vertical connector that is on the left side of the fuse block to the C320 connector in the trunk as the turbo car has an additional wire to power the fuel pump. Since I did not have the tail light harness for the turbo car, I just added the additional wires to the harness I had, and wired in the correct connectors.

Since the fuel lines are mounted on top of the frame in the back and I did not feel like raising the body at this point, I used flexible braided stainless steel hose for the high pressure side feeding a turbo regal line down the driver side at the fuel filter.

On the passenger side I spliced the lines from the turbo Regal about midway in the frame rail, leaving the lines alone in the back where they cannot be accessed. When installing the turbo Regal fuel tank just make sure to use the correct lines for the air vent and return fuel line. Since the tank is isolated it requires longer bolts with spacers to make up for the rubber strips that wrap the tank. Need a turbo Regal tank with the interior baffles with the appropriate sender/punp unit.

Overall it was a fun project and I'm still finding bugs that I'm working out.

 

[57loboy]

Lloyd - thanks for the post - great info! I hadn't considered the size of the heater box as the #6 is a PITA in the turbo car anyway - don't want to make it any worse! Was the ss fuel line you used some bulk line that you spliced/tapped in, or part of a kit of some sort? Do you happen to have any pics of your swap?

 

[Turbo1dr]

Different heater-a/c case? You sure you aren't mistaking the heat shield on the turbo car that makes it appear the box is different? You can swap just the heat shield over to the regular case. I believe the cases are the same.

 

[57loboy]

I have both cars side-by-side in the yard right now and other than the heat shield and stickers, I see no differences in the actual cases themselves. I have a complete spare unit from a V6 car that matches too... Loyd - could you give us a pic or more details - I am curious about what you encountered. Thanks!

 

[57loboy]

Loyd - I have started to swap the wiring out and have the dash out and am working with those harnesses now. QUestion - what did you find to be the easiest way to get the wires out of the fuse block that are part of the option wiring? Those clips that hold the individual wires in the box are a PITA otherwise....

 

[Turbo Loyd]

You many be fortunate as the heater box in the 86 Regal Limited was definately different with a slightly wider AC evaporator. I did not use the heat shield once I changed the heater box anyway. Take a look a the differences in the heater boxes

The box pulled out of the car
http://chicagolandbuick.org/images/PA310503.JPG

The one in the car now
http://chicagolandbuick.org/images/PA310501.JPG

Look at the positon of the evaporator canister fitting on the outlet line.

If yours is the same you will not have to go through that hassle. Believe me I would not have done it if the AC units were the same.

The option wiring harnesses have a tab on one side to unlock then they slide out

 

[Turbo Loyd]

Uses stainless steel braided fuel line fit over the 3/8 fuel line. I used Earls fittings and a compression fitting on a short piece of old fuel line going into the fuel filter. I connected the other end to the fuel line group that has the connection above the differential.

Just got a four foot section an Earls fitting for one end with the compression fitting. Hose clamp on the other end. Nothing fancy.

 

[HI85WH1]

Since I am about to undertake a similar swap on my 84 MCSS, I pondered the thought of using the entire frame with all the running gear from the T/R and sliding the unit under my Monte...