OK, lemme try it this way..

My Nova(now sold), has had the same 359 in it since 96, Be re-ringed 3 times, and it got mew bearings every winter.

Off the top of my head, I dont know stock GM cam numbers..
BUT, the cam I was tunning in this motor, was, .555 lift(with 1.5 rockers, I used 1.6), 325* advertised duration, (the numbers worked out to 306 @.050 lift or something with the 1.6 rockers),
Anyway, thos enumbers are basically a brqacket cam, intended use, drag/bracket racing..
Didit affect reliablity, well, sorta, it wouldnt start in anythign under 60*, and it coulnt idle at anything less then 1800 rpms without shaking itself to death, and then stalling...

BUT, did I know it was gonna do thta, yes, there is so much duration there, you have to expect that...

In this instance, I was refering to Somehitn glike RV camshafts, off road cams, adn regrinds..

There isnt much difference in these from stock, regrinds for obvious reasons... Those other cams are designed for lwo end torque, adn throttle response, where my bracket cam was deigned to get the most air into/and out of the motor possible...

So, in a regringd,/RV/Off Road cam, you shouldnt expect any reliability issues, when you start getting much larger than those though, your options vary....

As for manufactures, they have to make everyone happy, and usually, the camsalready installed in motors, are pretty right on..hence why the can re-grind a cam for different performance.. and the whole emmissions thing...

I can discuss cam timing and it effects all day, going through different types of profiles...

But, lets stick with the topic at hand, regrinds.. they are not large enough to produce anythign more than a little more oomph... I hopethis is clear... now.. sorry, I know I leav it a little vague...

Chase