For the record, the "bike chain" oil filter straps will not stand up to 50 ft pounds of torque. It exploded before it hit 35 or so. The steel strap ones do better, and (sorry from memory) that torque spec for that crank nut is lower then 50 foot pounds anyway.
As I recall, right about the time the steel oil filter wrench was starting to come apart (the biggest beefiest one I could find at the auto parts store... $7 or something), the torque wrench was pretty close to where the manual said the spec was for that nut.
I was erring a little on the low end of the torque range anyway (with lock-tite red), as a previous owner had buggered up those threads on the crank anyway and I was hoping they would hold (they did, I was lucky). That saved me having to cut threads for the next size down and finding a new appropriate crank nut.
We just finished a set of mods for the bike last night and had the first test run, I'll post that on another thread, it turned out pretty well.