My 1980 242 DL M45 manual transmission with 143k+ miles on a broken odometer has a lot of oil at the top of the water pump and below the top water pump o-ring seal and the upper water pump o-ring seal is swollen and visibly extends well outside of it fitting. However, pressure testing the coolant doesn't show leaks.

Nevertheless, I'm going to change the water pump and the timing belt along with all of the oil seals and timing belt tensioner.

However, I've never done a timing belt on this car, though I've done them in the past on my B230F engine Volvos.

The brickboard FAQs

https://www.brickboard.com/FAQ/700-900/EngineSealsBeltsVent.htm#Changing_Timing_Belt_Bolt_Removal

indicate that the rounded tooth timing belts (1994-1995s) last 100k, whereas the square tooth (like my 1980) last only 50k. If I install rounded junkyard cam, intermediate, and crankshaft sprockets from a later B230F engine and a rounded tooth timing belt, would that setup work in my 1980?

I notice that the fan has a large, central bolt instead of the 4 studs that connect the fan to the water pump as in the later model 240s. Do I merely use an impact drill to remove and later reinstall the fan?

Finally, Bentley, p. 215-3 is unclear. It accurately depicts my crankshaft pulley as having six smaller bolts surrounding a larger bolt (24 mm per my measurement).

The crankshaft pulley looks like this:

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSjeCOYlIgG4aPKCW9LiXJsp9fWf_Wv7vf20ge2ooIRJRZYoNZZdg

I want to change the crankshaft oil seal. Bentley says to remove the 6 smaller bolts to remove the crankshaft pulley. I get that so far. What I don't get is how to remove and correctly torque on reinstall the camshaft bolt. I have the IPD tool 5284

https://images-na.ssl-images-amazon.com/images/I/81XVD5UE57L._AC_UL160_SR160,160_.jpg

that does a great job of holding the B230F harmonic balancers, but it won't work here, because the crankshaft pulley is solid and without the holes for the 5284 to fit into.

Can I upgrade the B21F crankshaft pulley to a B230F harmonic balancer?

Thanks!