timing belt report

Just thought I'd share a couple of things on the timing belt and tensioner bearing change on my 1977 308. Did it last weekend with the help, encouragement and advice of my friend and fellow Fcar owner Mike McFarland.
1) Previous service had been done on October 15, 1997. Miles driven in that time: 7,327.
The belts (ISORAN) looked OK/normal though they were more pliable and less stiff compared to the new ones. I could detect no stress marks, no teeth wear. One bearing (SKF) was smooth and quiet, the second one was rough and felt like it had no grease left. Mike and I concluded that it had NO life left and that would be an imminent failure. Based on this experience I plan to change my belts and bearings no sooner than every five years.
2)The belt and bearing change took several hours longer than necessary because we decided, on the first belt, once installed, to rotate the engine (clockwise of course) by hand until the Sharpie markings made by us to reinstall the new belt, reappeared coinciding with those made on the cam and lower bearing sprockets!! After blisters on our hands we decided to disable the ignition and used the starter. It took a while, but finally turned the engine over enough times so that our markings all matched. Don't know how to figure out mathematically every how many revolutions this happens but it's a bunch. Given that there are two larger sprockets and one small one, god-knows-how many-teeth in the belt, the number of revs can probably be calculated by someone more adept than me. Needless to say, we made double-dog sure that the second cam belt was correctly positioned to begin with and rotated the engine by hand a couple of times, but stopped at that, confident that we'd done it correctly.
The car runs great and I'm glad that chore is behind me for many miles and, at least five years.
We used Verrell's cam locks which added to the comfort factor.