Hi Kelly,
AOD= Automatic Transmission (I "think" it stands for Automatic OverDrive, but since I've always driven a standard, I'm not 100% sure.)
ATI= The only ATI I've heard of is Accessible Technologies Inc., the makers of my favorite blower, the P1SC Procharger
Fox Bodies= the previous generation Mustangs (82-93 I think)
SN= Usually referred to as SN-95. The 94-98 style Mustangs
Modular Motor= The modular motor is much different from the pushrod 5.0 engines. The last 8 cylinder pushrod production Mustangs were made in 1995. 1996 and newer 8 cylinder Mustangs use the 4.6 modular motor....
If you'd like more specific info on the modular motors and vehicles, I'd suggest posting in Modular Madness...
