what to look for in a foxbody..

get a notchback, they are sexy. Look for warped rear quarters/ broken/ abused torque boxes in the rear. These will tell you whether the car has been beaten. Rust, if tranny grinds. All the lil stuff like lights etc. Any weird noises from the engine. All the basic stuff.
 
a notch is the lightest, GT vert the heaviest.

check torque boxes, seat mounts, etc for rust or tears. up till late 92, they had forged slugs - hypereutectics after that.

cheapest way to get times is likely to find an HCI car. normally one cant recoupe all of one's costs for such upgrades come time to sell.

good luck.
 
I don't have any pictures of the torque boxes for you. But there are two other areas that you want to look at or ask questions about.

1) The Heater Core - when was it replaced last? They tend to go every 60K ~ 70k miles

2) The Doors - the hinge pins can get bent / worn out over time causing you all kinds of headaches with sealing issues.

Other things that I always like to check are for full function of headlights / wiper motor and washer fluid. Seat belts extract / re-tract without any issues. Look to see if the seat mounts (on the floor pan) are not destroyed, although most of them are because it was a poor design.

Good Luck