I have to tell you, you need to be a die hard custom dude to put up with no drip rails. I removed them on my truck when I chopped it years ago, it sucks in the real world with the door being filled up with water and you open it to dump on your head. I am rebuilding the truck and I will be retaining them this time. On your Chevelle, it is sandwiched between the roof panel and the one under it. Not only that but the roof skin hangs out over the lower panel. So cutting the gutter off is a BIG project.
Think about this one long and hard before you do it. It is a LOT of work for very little pay back, does it really "improve" the look of the car? What other custom treatments are you doing that will add to the overall look of the car?
Personally, I don't believe without MANY other serious body mods is it work it to customize a car like that, it just doesn't improve it enough to be worth the work. Look at the photos below of something similar I came upon at a car show. It was stunning, and it took a LOT of work doing MANY modifications to make it walk over and stare at it worthy, you know what I mean? Just shaving the gutters and it would have looked like every other El Camino, is the work worth it?
The photos I took of that car mostly reflect the high level of detail to panel fit and finish more than the custom features. Though interesting, just the fit and finish is what grabbed me about the car, the level of passion was hard to beat.
Unless you really know these cars well you probably don't even know what was done to this El Camino, but a ton of stuff was done, it was a stunningly detailed car, I am always drawn to these cars that ooze passion. This car most certainly oozed passion. But if it was just really nice, a super nice car with ONLY the gutters removed, how much better would it look than one built as well but with the gutters still intact? I don't think that removing the gutters and even a few other mods is worth the work, it just doesn't make a big difference looking at the car. Just thought I would toss out some thoughts on the subject. Spending the time to make a mod like removing the gutters is better spent on pure detail, just making the car better on every square inch, that makes more sense to me.