I don't have an LT-1 so to speak, but when I built my engine, we ran the wires neatly behind the block and through the mounts as was done in the factory. That was a mistake as it turned out; you cannot access them easily to see if your have a short or anything. I plan on re-doing the whole kit-and-kaboodle in the next week or so anyhow because I am changing my entire engine management system to the
TEC3 system, which uses individual coils. If I was building it again though, and using an HEI system, I wouldn't concern myself with appearance as much as ease of maintenance; I'd run them over the top of the engine somehow.
_ken