1) would like to know if a dash and center console from 82-92 f-body will fit into an 80 el camino-would really like the floor shifter and the covans? dash cluster

2) would like to know if a 10 bolt rear from a 73 el camino will fit in to the 80 elky

3) would like to know if some shorty headers for 82-92 f-body will fit in to the 80 elky with 350sbc  

1) how good are your fab skills?

2)no.try a GN housing.better yrt a 8.8 ford with aftermarket axles.

3)depends.yes if they are hedmans- you plan on running their Y pipe?  

1) Not without a bunch of fab work and some major tweaking of the F-body parts.

2) Again, not without some major fabrication work. While a Grand National rear woudl be better, it's tough to find them. Aside form finding a stronger G-body based rear (like maybe a Monte Carlo SS, or lucking out and finding a GN rear) any existing stronger rear is gonna need some fab work to mount in your Elky. If you've got money, I believe Moser or someone sells a 12-bolt housing designed for G-bodies.

3) They might, but late model headers are chassis specific, so they're designed to run around the steering box and other chassis parts. You're better off getting headers specific Elky.  

1) how about just the center console  

why not use a monte carlo console