Changed my noisy fiber/metal timing gear recently to a quiet Mr. Tom McEachern aluminum timing gear while engine was in car.
(If metal timing gears are researched on the other Model A Forum, a few years ago there used to be a typical Model A Heresy that all metal timing gears, (bronze or aluminum), were unbearably noisy until one (1) Model A Forum Cleric on the other Forum protested & launched an adamant verbal crusade that Mr. Tom McEachern's metal gears were not noisy if one used his metal timing gear with his metal crankshaft gear -- then a few remaining Forum Clerics changed the Model A Forum Dogma after a few tried his quiet metal gears).
For timing gear removal & installation, here are a few tips:
1. Place a piece of wood between the oil pan & mechanical jack, (not a normal leaking hydraulic jack), to protect the oil pan; then, slightly lift the engine to remove the front engine support & timing cover.
2. Naturally, the fan belt & generator has to be removed -- don't forget the hidden "recessed" timing gear cover bolt.
3. Broke the plastic handle off of a 1/2" socket type screw driver & turned same with a small wrench to get to the tight areas for front oil pan bolt removal.
4. To avoid neighbors calling 911 because of (4) letter word usage, with a mirror, align existing timing marks on the timing gear & the crank gear "prior" to removing the existing timing gear -- makes it so easy to re-install the new timing gear & not having to rotate the engine a hundred times for new alignment of angular gears while fighting with a mirror & using (4) letter words.
5. Be careful not to damage the oil pan gasket & front crankshaft seals when removing the timing gear cover.
Others may have more to add -- just takes a little thinking associated with a little patience.
Added note: If you want a total lengthy renovation project over the next few months, just jack up the front of the engine high enough to crack the flywheel housing at the rear engine supports -- some loosen the rear mounting bolts for extra precaution -- others don't & lift the engine only very slightly.