[Psyekl]

Well, dang: there is no ID tag on the rear differential so now I have to calculate the gear ratio the "hard" way. Unfortunately my driveway has a severe slope (and I have no jack big enough here at the house) so it'll have to wait until I move it to my shop. Does anyone have any suggestions for what would be a good ratio for pushing a heavy truck/RV with the aerodynamics of a sheet of plywood down the freeway most efficiently?

I know how to calculate the ratios, but I have no clue what ratios to look for in rear ends or transmissions (I'm fairly competent with engines, but the toothy-wheeled spinny bits confuse me).

As mentioned before, the chassis is simplicity itself. When I pull off the body the work should progress very quickly as long as I plan properly. My desire to swap the front to disk brakes and power steering hasn't changed, and I'm also going to delete the fan and replace it with an electric. Since my shop partner builds hot rods and race cars It'll probably end up with headers/custom exhaust as well with whatever other custom doo-dads and bits/bobs we fabricate while it progresses. I'm not looking to build a hot-rod show-car monster, but it would be nice to have something unique to show off.