Yeah, one of my businesses buys 99% IPA by the 55 gallon drum. I wouldn't stick it in an engine, though. It makes a great source to clean out parts. For example, I have a '77 280Z with RB25DET in it and I used a massive Jaguar V12 oil cooler for the project. I hooked up lines to the old oil cooler and circulated a 1 Gallon can of IPA through it for a few hours to break everything up and clean it out before putting it on the car. If I were you, I'd save a good amount just for those kinds of things. It also makes a good cleaner for the surface of the deuce right before you paint it. Likewise, you can mix it with a certain amount of water as a wetsanding mixture ; the more water you add, the longer the evap rate. You can adjust it to suit. If you also add just a tiny bit of dish soap to the IPA/H2O mix, you have a professional spray to install decals. The soap will make it slick to squeegee out bubbles and the IPA will cause all of it to evaporate away.