impact

quick question for you guys. i am looking at setting up a true dual exaust on my car. the car is a 86 GXL.
i need to know if this:
http://cgi.ebay.com/ebaymotors/ws/eB...tem=2456406770
could be the same as:
http://www.racingbeat.com/resultset....rtNumber=16127

i know the first one is a 12a. but in the second link, at the bottom of the page it says something about fitting on a 12a and 13b.

i just bought the car about 5 months ago. an havent really started to work on it. cause i paying it off. now that its payed, i am pricing some **** out and getting parts together.

thx.
-kevin