If the distributor gear was at the back of the cam you wouldn't have any problems.
(Sorry, GM guy having a dig at you Ford guys).
One thing I think people often don't take enough care to do is checking the engagement of the ditributor gear. We just stick a new gear on the end of the dizzy and drop it in. When we get a new set of diff gears the guy installing them goes to great effort to make sure the tooth contact is in the right spot. We should take the same care for the distributor gear.
You don't have the same range of adjustment as a differential but you can adjust the height of the gear in relation to the cam. Have a look at the wear patern on your existing gear and see if it's biased towards one end of the tooth or the other. By adding shims between the distributor and the block can raise the distributor or machining it's base of you can lower it. Getting the contact patch even across the gear will mean the center and strongest part of the tooth has the most engagement.
That tiny little gear gets a lot of punishment especially when you use a high volume or high pressure
oil pump in your engine. The manufacturers have engineered this failure out of the newer engines. A lot of your more modern engines don't have a distributor any more (My LS1 doesn't have one). Plus the
oil pump is often driven directly off the crank.
Cheers