[skyking]

Thanks Phil, I was just looking at the template again when you posted. The back of trailer and is about 63% or so. Essentially I'm going from a high point of 7.5' and following the template for about 16'.
I'd have a clean break there with a bumper recessed in out of flow, and the ability to hang a 3' boat tail for longer trips if it would do any good.

I have weights in mind. The combined weight should be between 11,500 and 12,000 pounds.
I have played with the calculator quite a bit. I figure I can get an average of .008 on the crr, using the best tires for each unit. I just discovered I can use the Bridgestone 381 with the really low crr on the trailer.
Just guessing from my results so far, I figure the Cummins 6BT at .29 thermal. The truck sucks hard at 34.5 ft and .44 cd. I think smoothing things up off the truck and finishing them off onto template with faired wheels should net the mid.2s for the combined rig.