One of the things I found odd when tearing down the engine in our 1993 Bonneville was the lack of gaskets between the heads & the exhaust manifolds. Both surfaces were machined & seem to have sealed well for the past 20 years - no odd noises, no carbon deposits in unexpected places, etc.

Was it normal to omit the gasket in 3800 engines of this vintage?

The rebuild kit I purchased came with gaskets.

My 95 was the same way. I dunno either.

rockauto lists replacement gaskets, ive seen on older cars/engines where they just disintegrate from the heat and age

I would have understood disintegrated gaskets, especially after 20 years. The head gaskets & the EGR gasket were all in pretty bad shape when components came apart.

There was simply nothing between the heads & the manifolds. I wasn't sure if this was normal, or if the car was assembled during naptime on the line.

My wife & I were talking about it this morning. I recalled that during one of our early rides in this car, I asked my wife'* grandmother (the original owner) why one of the rear doors had cloth upholstery when the other door was covered in vinyl. (This was right after she had bought the car.)

She kinda scratched her head and said "Uhhhh ... I dunno." and she went back to the dealership, where they scratched their heads & said pretty much the same thing before replacing the vinyl panel with an upholstered one.

i can understand a different door panel because its there and something the workers are use to looking at just not two different ones. but if there were no gasket when new they would certainly know it the first time the engine fired