I would think a diesel 700R4 would have a much lower stall speed to hold down the "R"'s and take advantage of the torque.Toni my trans guy told me awhile ago is the biggest problem a 700R4 has is it doesn't circulate tranny fluid very well while locked up.That is one of the main reasons while towing in other than flat land even with a cooler you tow in 3th.I got to wonder how the wt of the RV effects that.Now I want to say that in my build plans I am going to use a TCI parts rebuilt 700R4 with a high torque 383 going in about a 4,000 lb Astro van towing a 3500 lb trailer.But in all fairness,we use to have a Suburban with Art Carr parts in it towing anything from a 6 x 8 trailer to a 22 ft trailer.We would check the fluid in Buffalo and go to Cleveland,Ohio.When we got back,you could see partials in the fluid and we didn't beat on the truck at all towing mostly in 3th.After awhile of owning Suburbans with 700R4's we actually on purpose bought a earlier model so we had the use of a 400 trans.As I think about this more,I think a 400 with the Gear Vendors trans is a better set up than the 700R4 with one.You could also get more feedback on this RV site.Look under the Vintage section for RV's.

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