Nano-Oil 85 weight is an alternative, though more expensive. In industrial applications 75-85 weight would be considered a gear oil like what would be used in a vehicle differential or transmission, don't think I've heard of anyone trying gear oil from an auto parts store for this application. Breakthrough Clean HP100 Knife Oil seems to get good reviews though I don't see a weight advertised anywhere other than "heavy". I've used some of their gun cleaners and lubes in the past and been happy with them. Extreme Force gun oil is also advertised as a heavy oil. Liberty Oil has complaints in the reviews that it is too thick/viscous for the needle applicator on the bottle so it is probably pretty thick. Slip 2000 used to be very popular in the knife crowd.
All that said, you kind of just have to pick something and try it. When you're getting into that kind of heavy oil, light grease could be considered as well. I've been very happy with OCD 4 EDC Slick 'em All. When it comes to any of this stuff, even the tiny bottles are pretty much a lifetime supply so the cost becomes more bearable. I have four various bottles of KPL that I use every time I disassemble and clean a knife and without comparing them to a new bottle you'd be hard pressed to tell they've been used.