Ok.
Here is a little update.
SC os off the car.
Noseshaft is toast ,coupler in small pieces.
Replacement on the way.
I seems to be stuck alittle with intake manifold.
It'* just one last bolt,but it seems to sit under some sensor.
The sensor looks identical as coolant sensor under throttle body and connector is on the same harness with coolant sensor under TB.
Here is location:when you stay in front of the car and face it it'* in the upper right corner of intake manifold. I'm lost as I can't locate it in FSM and FSM removal procedure not even mention it. I don't have appropriate tool to unscrew itbut will try.
Just want to make sure I'm in the right spot.

Yup. S1 Bonnevilles have two coolant sensors. The one on top of that intake bolt controls your gage on the dash. 3/4" deep well will take it out.

You have two coolant sensors. The one in your way is for the gauge. The other one in the end of the LIM under the TB is for the PCM.

A large deep-well socket or a wrench will remove it. It must be removed for access to that LIM bolt.

Use a small amount of RTV when putting it back later to prevent leaks.

Did you spin the rotors by the pins to make sure things are OK?

Ok.
Thanks for info. I will take it out.
Yes I did spin rotors.There is a little play when pushing/pulling gears,very minimal ,but I guess when nosedrive will be in place it won't let it "dance".

EDIT: Maybe that play isn't play at all,just rotors a little bit out of housing.
I was banging it with rubber hammer to loose nosedrive.

So it'* 3/4" deep socket?
I'm out to the store to get one. Thankfully store is three blocks from where I live.
Was there three times already today

Needed some deep sockets,8mm nuts ,draining pan etc.
All is 5 min walk away.

I 'm probably done for today. Going to remove and reinstall manifold tomorrow and will be waiting for nosedrive.
Now will have to catch up with some oter things.

Update

Changed IM gasket this morning .
The old one didn't look bad,but one of those rectangular windows (I gueess for coolant flow) has a slight damage.
It'* located near cylinder #5 so maybe this explains why I had random misfire on #5.

Went to dealer to get SC gasket--not in stock.
He ordered from some place in Manhattan,I guess not that many of Bonnevilles needed this part here.While out,postman left notice-probably coupler and oil arrived.
Rollingperformance.com sends it from NJ so it'* right across the river.
Hope nosedrive will arrive before noon on Thursday so I can finish it on that day.
Dealer didn't have red gasketmaker either,but I saw same red gasketmaker,just not under GM brand in autoparts store.

The only pain in the neck will be tomorrow to unscrew nut from SC pulley.
It has to be hold somehow,noseshaft is lose.
Don't know,will try.Basically I do everything "on my knee".

Will post new updates upon availability.

Rain all day long. :(

Is 8 oz of SC oil enough or better to get another 4 Oz bottle just in case?

You will only need one bottle. Half the capacity of the M90.

Ok.
Thanks .
I got two 4 Oz bottles with coupler today.
According to Fedex tracking web site nosedrive will be here tomorrow so hopefully it will be the end of this project.

RP sends two bottles because that'* what the M90 takes. You have a spare now.