Will these cables work on my diesel truck?

Yes. The 250 amp rating covers gasoline and most diesel engines. If your truck exceeds 250 amps at cold start, upgrade to a 400 amp rated set.

Can I store these coiled up in my truck bed?

Coiling tight stresses the copper-clad conductor and can cause internal breaks. Loop them loosely or use a cable bag to prevent kinks and maintain conductivity over time.

What clamps are on the ends?

Clamp type is not specified in the product data. Before your first jump, check that both clamps grip battery terminals firmly and make full metal-to-metal contact — a loose clamp kills amperage flow.