Another option is to cut off the threaded part of the post, which will add another 3/4 in. of clearance, and use a standard automotive style connector on the fat part of the post for those 2 batteries.
Regardless, some kind of insulator will be fixed between the hood & those posts.
Almost forgot to mention: sold a couple more ICE parts. The 1.3L engine (finally) and misc stuff from the red car. $90. That sale represents a healthy portion of the net cost of the project to date!
Also have a deal pending (touch wood) on the gas tank from the blue car. (It was replaced a couple of years ago).