hmmm - I'm kinda with Longbox Bill, Stuart and WhoMe - seems that the folks who've had problems they attribute to the oil formula change have fresh engines, with who-knows-what cam/valve assemblies, NOT folks with high mileage original engines that keep chuggin along regardless of even getting oil changes, and the folks making the fuss over it are the hi-po crowd stressing the design for greatest fuel consumption
my 235 had 50,000 original miles when I got it, after another 35,000 I put on it, still runs fine - the 58 with a rebuilt 283 [stock except for overbore] is also running fine ..... if it takes as little as 500 miles to ruin a cam I musta got one made of kryptonite or something
Bill