Reply to "My Weekend at Willow Springs"

A few possibilities:
1- If you've recently changed distributors from any source, be aware that a 351W distributor WILL fit in a 351C..... but the smaller diameter Windsor gear will only engage the outer 0.060" of its teeth on a 351-C cam. This may (if you're lucky) last for 200 miles before the gear teeth on the distributor rip off.
Second possibility: some aftermarket cams were made with the 'pressure angle' of the distributor gear on the new cam ground at the wrong angle. The result is, the distributor gear teeth fail; one wore to razor thickness in only 5.0 miles.
Third: there is an oil passage in the front of the block that comes off the second drilling of the front cam bearing. If the front cam bearing is installed wrong, that passage will be blocked and no oil will squirt onto the distributor gear/cam gear mesh. I have heard of distributors siezing from lack of this oil.
4- engines that run high pressure or high volume oil pumps put far more load on the distributor gear than a std pump. In some cases, this is enough to radically increase gear wear.

All these scenarios will pump metallic slop through the engine and do bad things to bearings and the oil pump. It may be a good thing to drop the pan and check #1 or 2 rod bearing (most likely to fail in a Cleveland), #1 main bearing, the crank journals on those bearings checked and the oil pump body, all for deep scratches.