72 Duster's new Filter location

I don't think the OP's long lines will drain out much, if at all, with a filter change since their ends are located up higher than the old filter location. And with a nice vertical oil filter mounting, you can pre-fill the filter to the brim and cut down any fill time.

I've run 3-4' hoses for years in my rally engines with no issues. Use 1/2" ID lines and calculations with standard flow rates show that you shouldn't get any more than about 1 psi drop. That is less pressure drop than in the passages and bends inside the block in the standard oil passages.

BTW, OP, if your line get any where close to the exhaust, wrap them in reflective foil to keep the heat out. Also, what line do you plan to use? I'd strongly recommend not to use stainless braided over rubber lines; you can never inspect the rubber under the braid and I've seen too much of that type of fuel line have tiny leaks from pinholes in the rubber. I also am leery of teflon lines for this particular use only because of possibly being too near to the exhaust. There is some multi-layered, fabric covered and reinforced oil lines that you can get from NAPA that is very durable as oil cooler lines.