Will this fit my automatic and manual Samurai the same way?

Yes. This radiator is engineered for both transmission types in this generation, and mounts at factory points on both. No adapter or modification needed.

Do I need any hoses or clamps?

The radiator assembly comes alone. You'll reuse your existing hoses and clamps from the old radiator—measure and confirm they're in good shape before install.

Can I use this as a core support for a custom build?

This is an OEM direct replacement, so it's sized and mounted for stock engine bay dimensions. If you're running modified power or custom plumbing, verify core size and inlet/outlet positions fit your setup.