What is the real torque value for the front crank bolt without special tool?

[Jimarilo]

Been trying to work out the best and most cost effective way to change my cambelt, without laying out on the crankshaft tools, to lock the crank and to torque the main bolt to 332lbs/450nm

Ebay item 233558349051 could be a solution and no need to lock the crank to release or tighten the main bolt ........£60