Engine block grounding location?

I'm planning on installing quick disconnect wiring for a (removable) front bumper winch.

I have a bus bar connected to the battery (+) terminal through an MRBF that I can use to supply the winch +12V, which should easily be able to handle ~250A.

I'm a bit worried about the grounding side of things, though. There's a pretty big wire between the engine block and battery (-) terminal, but the wire between the battery (-) and chassis is pretty small - looks like maybe a 4 gauge wire or something. Not something I want to run 200+A through. I looked for a direct ground wire between the engine block and the chassis, but I didn't see anything, and based on the resistance readings on my DMM I suspect there might not be any additional high-capacity direct connections between the engine block and chassis.

I have an extra 2ft 1/0 ground cable lying around, so I'd like to run that directly from the engine block to the chassis.

Question is, where's a good place to connect a ring terminal to the engine block? A lot of the bolts on the engine block are torque marked, so I don't want to mess with those. I'm leery of messing with random bolts on the engine block in general, and a lot of them look like a PITA to get in and out.