High torque manual gearboxes

[Emolloy93]

I've got an American truck engine sitting in my shed which is just begging me to swap it into an offroader to make a stupid weekend toy, but the problem is it makes about 300lb-ft at 1200rpm and heads up to 425lb-ft at 3000rpm.

I know there's a huge number of autos that could take that no problem, but I'd prefer to have a manual for the fun of it. So far my searches for gearboxes that could take the torque seems to be limited to big American pickup gearboxes which are hard to find here or luxury diesel cars like BMWS but the ratios aren't great for low range.

Anyone got any suggestions for a suitable gearbox that won't just blow up? Bonus points if it's got a transfer case as well.

[Snow and Rocks]

Obvious answers are the boxes fitted to straight six Land Cruisers and Patrols?

No idea on the technicalities (or cost...) but they've both got a reputation for strength and durability and come from the factory attached to pretty grunty engines that are easily and successfully tuned.