You wouldn't be measuring up for one of those siminted lippy thingys would you? The max torque figures for the half-shafts that I got from Euro driveshafts convinced me not to fit one with my Jag diff, but you might be OK with a standard (Triumph) lump.
For interest: 1310 (Peerless Driveshaft) Torque Figures are:- Constant Torque 176Nm (129 lbs ft) Short Duration Torque 1085Nm (800 lbs ft) Maximum Elastic Limit Torque 2200Nm (1622 lbs ft)
You start with about 100ft/lb at the flywheel then multiply it by the gear ratio (1st = 3.058) and the diff ratio (3.7). This is why people break driveshafts at Santa Pod after they've travelled about ten yards, it happens in bottom gear as the engine gets to peak torque. I'm told that for us regular mortals the tyre breaking traction with the tarmac is the "safety valve" that prevents the driveshafts knotting, but if you are running something wide and sticky......