I have run them this way for years. Your headers/exhaust and plug wire length decide if you can do this with or without looms. I always use full length headers so I am not familiar with doing this with a hot collector flange anywhere close. When I purchase my wires I do not use the prefab ones. I use 90° boots and make sure the lengths are cut to hang properly. I do use the clip on looms that just go from wire to wire holding them equally apart but I have run them without. It just looks better to me when they are equally spaced running beside the block. I don't have any looms mounted to the block etc. Chevrolet did do some like these from the factory but I don't have any idea what the part #s of them would be.