Good engine blocks for a build

[BADAZ chevy guy]

So, I have the transmission (4L60) rebuilt so I have a driver once again. Now I need to start collecting parts for the new engine. This is for a 77 C10 short box. I'm torn between a 350 or a 383 but in either case I want to find a decent starter block. What block casting numbers do I need to avoid at all costs and which are ones to keep an eye out for? This is going to be a daily driver. So, the engine isn't going to see much, if any, racing. I just don't want to get her all together and find a puddle of oil from a major casting failure.
Thanks in advance.

[Engineer]

68~69 350 blocks are thin, light castings.

After that anything block wise will do pretty good. I wouldn't be afraid to use anything after 1969 if it magnafluxes out good.

70~72 blocks are supposed to be high nickel and should last longer.

[Captkaos]

Ditto on the above.  I would run anything as long as it  was a large journal post 68/69 block