Looking for a book
Many here know a good bit about small blocks. It’s all I ever really felt with. Cheap, popular, ez to get, lots of used parts available.
Ask, I and others will answer.
The Magnum is the same thing except minor differences. No head oiling. Heads have a different rocker system. Intake bolts go straight down. Timing cover has no provisions for a mechanical fuel pump.
A Magnum block would be a great foundation to a stout power house build.