Dimensions Needed for After Market Cats

[Roncallo]

Among other things I'm in the process of properly fitting cats to my M120 107. Right now I'm using the stock 1996 SL600 129 cats. They work well but do hang a little low occasionally can get hung on my 4 post lift if my tires are slightly low. So I'm in the process of modifying the floor to accept both the 129 or aftermarket cats with a more professional fit.

The problem is the manufactures give you very vague dimensions. Some have a heat shield and you don't know if the heat shield is included in the dimension or not. Most with heat shields have a flange around the edge and I'm not sure if that edge is included in the width dimension.

Eastern Catalytic gives you the box size the for the CARB compliant cats and a cryptic dimension for the non CARB cats. Magna flow just gives you a text the dimension.

But it does appear that each of the manufactures has only about 3 or 4 main body dimensions for width and height and heat shield stand off. If I can get those dimensions I would essentially have the dimensions for 100's of cats.

The first picture shows a cross section of a 107 floor with all interfering structure, including the floor, tunnel, tunnel lower plate, drive shaft and parking break. There is not much room to play with before hitting a drive shaft center bearing or seat bracket attachment of parking break cable. The picture is shown with cats from Eastern (wide) and cats from Magnaflow (round). The green part is the original floor. The yellow is the proposed floor modification for an Eastern Catalytic converter model 70530

The third picture shows the dimensions I need to accurately make these drawings. The dimensions that are in picture 3 are my ASSUMED dimensions from what I got from the Eastern Catalytic specification shown in the forth picture.

So if anyone has any loose known universal catalytic converter and can measure the 5 dimensions on the third picture. It would be a big help to me and I'm sure others on this forum.