Hello!
Before converting with datsuns, I was playing with mini's a bit. There was a great techincal book called "Tuning the A-Series Engine" by David Vizzard (BMC a-series engine, not datsun a-series). It covered just about everything you wanted to know about those little critters.

I was wondering if anybody has or knows of a good technical book covering the early datsuns ??!! I'm not talking about the standard type haynes or gregories type maintenace manual.

If there is nothing specifically for datsuns, what would be the next best thing?

I bought that same book. I bought it for the SU section.
There is a B110 Competition Manual that's very rare. I've only seen it on Ebay once and someone on this site paid hansomly for it.