['63GENIII]

Brian, in one of your first pics, I noticed a "pigtail" coming off of your + and - battery terminal clamps. Is the - pigtail connected to anything? If not, Id also consider doing so. I have mine grounded to the radiator core support to provide a body ground.

My + pigtail is routed to the horn relay + side as well then travels to the fuse panel.

I do see that it appears that your - battery lead is going to the alternator bracket. That is fine but Id scuff the paint under that lug to expose some clean metal there. Just think that the current / voltage needs the cleanest uninterrupted path when completing the circuit. Battery to solenoid, solenoid to starter motor, motor through starter bolt to block and back to the negative terminal on the batt. Any loose, painted, corroded or weak connection in between WILL compromise your starter's operation. There are a lot of links in that chain. They all have to be just as good as each other.

Have you been able to take your + cable directly to the starter to eliminate the battery disconnect as the problem? Thats a free test and another weak link.

FWIW, as far as the newer car grounding, they have a ton of straps seemingly everywhere. Our '04 Denali has at least 7 that I know of that are the size of the one you show. The Battery - cable goes directly to the block. The computers (which run constantly) need way cleaner and more grounding than our old trucks. Kinda like comparing an abacus to a MacBook.

One other thing about mini starters vs standard. While I do like a good mini starter (the LS engines come stock with 'em), keep in mind that the GOOD quality standard and heavy duty starters have been starting the likes of high compression L88's and LS7's (the real ones - non LS) for years without fail. They can probably be a good deal cheaper and less complicated.