Why would I want a D34 instead of a D34/78? Seems to me it would be an advantage to have both types of posts, no?

Thanks,
js.

 

I have the Optima Yellow top with both top and side posts. The side posts are perfect for adding additional electrical loads like lights, Amateur Radio, etc. without disturbing factory wiring.

 

If you plan on using a winch you'll want to use the large main lugs for the winch. They are capable of handling the large sustained current loads of the winch and use the side terminals for the factory connections and any accessory's. The factory connections only see a large load under the temporary time of starting the vehicle.