Not sure what you are asking. Using
https://www.sdtrucksprings.com/ and drilling down the vehicle search you would choose the E450 Commercial/Motorhome selection. There is only one listed for the front and rear. The front one covers 1997-2007 and the rear covers 1997-2021. Both of those are Hellwig's.
I installed the front on my 2007 E-450 and it made a vast improvement. After a couple of trips I installed the rear. I could actually go through a corner without that rolling over feeling.
For sure try to get the caster set to 5-6°. My alignment guy got mine right to 5° IIRC. Even Forest River was telling customers to do that. It can be hard to find someone that will do MH unless you can find an old timer that knows their stuff and has door height. You might need to find a shop that does heavy truck frontends.
I have used
https://www.sdtrucksprings.com/ several times and their customer service was good. It used to be if you called their help line and asked a product question (make one up) they would answer you then say if you order from me now I can give you $$ amount off. Worked for me!
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