BBK shorty's?
 

Is this a good price? And are the cat heat shields absolutely necessary? Does anyone know if this is a bolt on -or- would a muffler shop have to put these on?

Price: $100.00
Brand: BBK
Part Num: USDBBK1538

USED SHORTY H-PIPE W/CATS FOR 96-02 MUSTANG GT AND 96-98 MUSTANG COBRA. THESE ARE UNITS WITH MISSING HEAT SHEILDS AND OR OTHER BLEMS THAT COULD NOT BE SOLD AS NEW.
11 UNITS AVAILABLE

Where did you find those? You said there are 11 available? I would be interested to check them out since they go for about $370 new with cats. As for the heat shields, I dont know what kind of negative effect it could have for certain, but I could speculate that the cats will not transfer heat as well. Maybe one of the others can give more info on that. As for wether or not its a bolt on, it is, but they only work with long tube headers. They will not bolt on to factory heads.