In order to determine if the Kwikee Electric RV Step Complete Assembly - Double # LC372261 will work with your 2018 Keystone Passport Ultra Lite Express TT or not, you will need to locate the space available underneath your trailer that lines up with the doorframe, and measure the width and depth.
You're going to need a mounting space that is at least 25-1/2" wide and 11-3/8" deep. If you have less or more space available beneath your doorway, then check out the list attached that shows... view full answer...
Since we know that your 2018 Keystone Passport Ultra Lite Express 175BH has 3,500 lb axles we know that the Dexter brake assembly set part # 23-468-469 that you referenced is correct for it. view full answer...