I need to replace both of my catalytic converters but i have no clue what i need to buy...i know there is 2 but when i was on summit racing they all look so different...any help would be great.

 

Are your shorty headers the ones that keep the stock cat converters on the stock locations? If so, you need a drivers side cat made specifically for the dual-cat LT1, with the big triangular flange to match the flange on the headers (which should match the stock dual-car drivers side manifold flange). That is the hardest replacement to find. Random Technology may make one.

If you have stock cats in the stock Y-pipe, they are welded to the Y-pipe. They have to be cut off, and rewelded (one weld on the driver's side, I think two welds on the passenger side. You might want to look for an aftermarket dual-cat Y-pipe, with high flow cats already welded in. Again, Random Tech may make one. Or maybe Borla???

If you do not have the stock dual-cat Y-pipe configuration, you need to match whatever was used in the aftermarket configuration.

 

I think Magnaflow makes a direct factory replacement. I recall them on Jegs.

http://www.jegs.com/p/Magnaflow/759591/10002/-1

I don't know how good they are or how they will fit, but they are cheaper than getting them from GM.