[Marky Dissod]

Do SS / 9C1 sways bolt up to the D bodies?

Hell yes.

I see them at times still in the yards and on here for reasonable rates, yes I know to measure first on mine.
All I am looking for is a set of OE pull offs from one of those, nothing wild.
Just hoping to tighten up the body roll a touch, not turn it into a Z51 equipped Vette.

Speaking of measuring yours first ...
Since your Fleetwood 2.93 is neither V92 nor V4P, your SPID sticker includes suspension RPOs.
What spring options you have (6?? , 7?? , 8?? , 9??)?
FE1? FE2? FE??

 

[Marky Dissod]

WTH's this got to do with swaybars?

As in, besides the fact that Katshot chose the FTS' suspension mods wisely?

 

[Marky Dissod]

... hearses have their own RPO ...

R1P: livery
V4P: 7000lb tow
V4U: coachbuilder limo
B9Q: hearse
B05: armour

 

[Marky Dissod]

When it comes to the LT1, or the 4L60E, much if not all of the ISSF is eager to improve on what GM left unaddressed.

When it comes to the frame, much of the ISSF is hesitant to improve on what GM left unaddressed, which means one never gets quite what they should from suspension upgrades.
About as succinct as I can put it.