No, I never rode my 400 with the original shocks. They were solid rust. But my 360 still has a good set of the original thermals and I can't really say I noticed one being better than the other. But all I do is ride around the two mile trail on my property, or blast down the gravel roads. I haven't negotiated a series of whoops or got air in over 20 years. I still remember the last time I went down trying to keep up with my boys while riding an XR600. I hit the ground before I knew what happened. Knocked the wind out of me. I couldn't even pickup a gallon of milk for at last a week. Probably cracked a rib and never did anything about it.

Dang, there I go telling a story again. Sorry folks.

As RT would say... I published an essay then pushed wrong button and erased it....
Before writing all that again what is your rear shock budget & expectations ? Hagons on my DT360

I am thinking 200 to 300 hundred. I would be happy with any of the shocks mentioned but I have not found anything that says it will fit my bike. I will be riding the bike on the street and very little dirt.

They may not list your DT360, but that doesn't mean they won't fit. That seller with the ASSAULT shocks has several listed on his eBay store. The eye to eye measurements range from 13, 13.25, and 13.5. The 13 inch would probably fit fine being a smidge taller.

I did measure my shocks and they measure 12 inches. Will the 13 inch be to long?

The shocks that are in the picture and on Schus 400 on post #3 would be a good choice because you will have plenty of clearance between the shock and chain / sprocket. My red wings on my RT have the spring tension adjuster much lower and there's very little clearance between the chain / sprocket and adjuster.