i recently had the same problem when changing the head gasket so before i took any of the belts off i marked lines on the belts and the cogs .then after taking the belt which goes to the top cog on the rocker i removed the spark plugs and placed a fairly long screw driver in number one plug and turned the crank with a spanner till the screw driver started rising and started to drop again and judged it to as close to it dropping again as possible be carefull though as the screwdriver will get fast so keep checking when the screw rdiver is rising that its free this should give you tdc hope this helps
stetaylor53@yahoo.co.uk, May 2007