I think you'll be all right for the installation. The wild card is that both Ford and Bigfoot can't be sure what your coach builder might have done.
BUT!!! My major point is WORK SAFELY. Support with steel stands or wooden timber. NOT "concrete" blocks. Get it high enough that you can work freely. I like cardboard, like major appliance boxes, moving wardrobes etc flattened out and used under there. It provides good padding and easy to slide around on. If you want to use a creeper the coach needs to be a couple inches higher. You may also find you have to get OFF the creeper to torque larger bolts.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB