visual differences between 231 and 242

i am having troubles with a trans shop that is going to install my sye and i bought it a while back to the tag that had fallen off the tcase. Well i got a call saying i have a 242 and now im trying to figure out how i can tell the difference visually

231.




242


the front half of the case is where the difference is. note the ribs on the 242.

thank you very much that is exactly what i needed