I did find it here but the shipping negated the good price. https://www.finditparts.com/products/3696034/j-and-n-240-22082

Local place said they have never seen one burned up by excessive amperage. I liked this one as it seemed to be about the heaviest duty one with large studs for the bigger cables.

Specs from Finditparts page

• 300Amps
• 2000 Amp Intermittent Rating
• (2) 1/2-20 Threaded Studs
• Indexing Pin Aligns Switch & Prevents Rotation