Buick Lesabre owner from the Netherlands

Like Luxus said. You can make it a little easier by putting a tiny bit of bleach in front of each of the rear wheels. This way you don't have mash the gas pedal. It's funner if you do though
The drivers side wheel might spin a tiny bit at first if it's not a posi but if it is a posi you should see two somewhat equal tire marks.

 

You would have to drop the tank but do you really want to?
I am not a paper work expert but I have seen members find build sheets at alot of strange places.
Could be behind the rear upright seat, or behind the the front seat in the springs. I think iv'e seen people find them under the rugs also.

The big issue though is alot of people find these build sheets when they tear into a car for a resto's.
The easiest way now is to look behind the rear upright seat in the springs. If you noticed when you pulled the rear sit down seat there should be two bolts on each side holding that upright seat down.
They might be torx style bolts, I can't remember. Unscrew those and the seat should fold up if memory serves me right..

 

No bleech, just a boot full standing still with a proper warm engine after an hour drive.

Just like you say. Passenger wheel full spin, driverside just a bit.

Clearly no posi.

 

Don't be so sure it not a posi. I might be completely wrong but I think I see signs of the tire hazing a somewhat equal length on the drivers side.
I have read about posi clutch wear or needed shimming??
Did you hold the car still with the brakes at first? I believe the drivers side shouldn't have spun at all.
Asking again if you saw any metal tag on the rear end pumpkin?

 

No did not hold the brake. Don't want to do a full burnout. Just standing still and floor it was enough for me.

Looked at the rear of the pumpkin but did not see a tag

 

Another reason that it's good to know if you have a posi is if your taking a turn and hit the touch the gas pedal even slightly you just might spin that car around.
Wet roads can be scary.

 

It should not be out driven when rainy or wet and I know the disadvantage of not having a posi. My previous car was a 1985 Rover Sd1 Vitesse which also didn't have it (also V8 rwd).

Thnx for the warning though

 

Got my new registration for the car

It now is registered as a 'Buick LeSabre Custom', with a 1st registration date of may 1st 1975 (the fishertag said 3rd week of may but he, it is better than 28 February ). Also the power figure was changed to 169kw / 230hp instead of 153kw / 210hp (1974 jumped from 210 to 230 when you added duals and mine has an catalytic converter-delete with the duals on top of it so 230 is not even that crazy to assume.

Still haven't gotten round to checking if it has a posi. Want to jack it up and see by turning the wheels if it has.