DIESEL dart :)

I have thought many times of building a 4BT Ramcharger. they get great mileage, bulletproof, and would be great in a half-ton. How come you just don't use an NV transmission? I thought they had the same bolt pattern as the 6 and the extra gears would be great on the freeway. rpm's with a good sized tire and rear gear would be quite a bit lower. also as far as the radiator you might want to look into one out of a diesel forklift like a linde baker. they are usually pretty narrow and are plenty thick, plus they can be found for alot cheaper than having a custom one made. if i remember right they weigh about the same as a small block so really the mods would be to handle the torque twist. I would do some downtubes from the firewall to the front rails, good thick frame connectors, a crossmember over the driveshaft and as far back to the front spring hangars as possible. maybe a simple 4 point cage just to attach the door bars close to the firewall to tie it all in.

I soooo wish I was close enough to help!!!