I'm trying to decide which would be a more reasonable goal for an engine to swap into my motor home. It's a 21' American Clipper class C motor home on a 1978 Chevy G30 van chassis. I'm afraid a 6.2 just won't have the guts to push it down the road with decent speed and acceleration, but a 6.5 is going to be pricey and harder to swap in. I hope to find a donor van so that I can get all the special parts that might be different from a diesel in a pickup or K5. I would like to find a turbo version since van turbos are hard to find anyway. I also don't want to spend a lot of time or money building up the engine as I have my work cut out for me already in restoring the motor home itself. I'd rather have one that will perform well in stock form, and the 6.5TD is much more up to this task than the 6.2. I guess I'm just asking whether the time and effort required to swap in the 6.5TD above and beyond the effort to swap in a 6.2 would be worth it. I'm also concerned about RPM's. I'm not sure how I'm going to get them down. With the current setup I'd be turning that diesel at 3600 RPMs at 65mph, which is definitely not a good idea! It would cost a lot of money to regear the D70, but would cost nearly as much to install a Gear Vendors or other type of OD unit. An OD transmission is out of the question. This seems like a huge project but I'm sure I'll be extremely pleased with the results, plus the cool factor of tooling down the road in an "old school" motor home with a diesel. Only 5000 or so American Clippers were ever produced, and less than 1/4 of them were on Chevrolet chassis, and none were diesels, so mine will truly be unique.