I'm in the process of installing a battery disconnect switch on my 29 Tudor. I sat and read every post on the subject by using the search. At first, the many varying opinions made it seem like rocket science to me, but I kept at it until it all came into focus.
I had already purchased what amounts to a 'kit' from Snyder's. That is, the switch, the mounting bracket and the extra short cable. But after reading all the posts, it was clear that it was better to install the switch in the positive or ground side, so another rethink was in order.
I'm still intending to install the switch under the hood by installing it to the lower starter bolt but to do that I need another (24") cable. Trying to find one at local parts stores was a waste of time. But now, I've found a seller on eBay who will supply any cable you want, in any length and with whatever fittings you want at either end. I don't know how to patch in the link here, but their name is: gaugewireandcable
I'm going to order a 1/0 gauge AWG copper battery cable, 24" long with a 3/8" ring terminal at one end and a top battery post connector on the other end.
Their prices are very reasonable. The quality sounds great, so does their service.
Check it out .... Dave