Long Block question

[C20mama]

Hi,

I'm new to the board and was wondering if someone could tell me the difference between long and short blocks.

I may be putting something new/rebuilt in my 69 Chevy C20. It has a large camper on back.

Are there any threads that talk about engine selection? I saw one, are there any others?

Do you guys have any suggestions on what kind and size of engine to put in there? Assume cost is no object (it is, but I'd like to hear about all the options. I can probably spend 3-4,000 on it)

Thanks