Is there a way to fit a whole section of floor in a 91 from a 69 can't seem to find one for a 3rd gen. I know that the torque boxes are going to be a problem but is the driveshaft and torque arm able to fit? Even if the rear is off center for those and is there anything else to be concerned about maybe where the trans bolts in on the frame rails?

 

Just my opinion, but you already identified a major problem - frame rails.
The 69 had them, the 91 is unibody - no frame rails.
Of course a really good fabricator can make anything work, but why do you want to do that?
http://autobodyspecialt.com/chevrolet/camaro/1982-1992/

 

hmm.... I thought they where all unibody in first and second gens i found a 69 reproduction floor pan thats got the whole sitting area for real cheap and instead of just sections I just wanted to drop the whole thing in and weld it in instead of trying to play where's waldo with the pieces

 

Maybe I am confused. Did the 1st gens have frames?
I know the 2nd gens had front frame rails that would unbolt from the body.

Edit: internet says front half is a "frame". Firewall back is unibody design.

 

1st gen unbolts like 2nd gen

1st gen rear steering box, 2nd gen front steering box

 

ah ok its a sub frame I can work with that I'll build a sub frame got it thanks guys

 

Third gens do not have a subframe like first and second gens. The frame rails are just thick boxed sheet metal that are part of the entire body structure. Third gens have a front crossmember for steering components that bolts to the sheet metal front frame rails. Third gens also use a sort of macpherson strut type front suspension but instead of the spring being on the strut/shock, it's between the lower control arm and the frame rail. First and second gens are upper and lower control arms with a spring between the control arms.

 

No this won't work.

 

Definitely not the the best approach, that's for sure.

 

Google it looks like Summit has them, CarID has them look around.

 

The amount of fabrication required would be a lot, by the time your done there probably wouldn't be too much left of the 69 floor pan.

1991 Chevrolet Camaro Parts | Body Panels | Floor Pans | Classic (classicindustries.com)