73 340 SB Rebuild, Need Help Selecting Parts

I've seen complete 340's that had no guarantee of running or not being worn out, but are complete and not blown up, and the asking price was $1000-$1200 in my neck of the woods. Finding a good block that is not all rusted up and can be bored on the open market for $300 is a good deal. On the other hand, I found a $50 360 LA block within 100 miles.

My concern over crate motors is not knowing or having any control over the build or parts quality. Yeah, you can mess up your own build fer sure! But you can control each step and each dimension too.

A crate motor or short block has some attractiveness if your engine building experience is limited; a good part of the work is done. But again, you give up some flexibility in the dimensions and such; for this app, I would be paying very close attention to the dimensions that control CR; IMO, moderately high CR without going too high is important for that broad torque range but not detonating.

I can see folks making either decision and making it work. I take a certain satisfaction in building from a minute level of detail but not everyone gets satisfaction out of measuring and managing things to that level. I do feel that good detail work produces better results and a stronger build.