I ran Valvoline Racing for many years in my daily driver TR3A and it worked just fine for me. I know the detergent level is supposed to be lower than 'normal' motor oil, but when I eventually tore the engine down, it was just as clean as you could ask for. Much cleaner than I've seen with other brands of 'regular' oil. No sludge or varnish anywhere.
I also saw something that really impressed me with the VR. As it happened, I pulled the pan and then let the project sit (in an open shed through an Indiana winter) for nearly a year that way. When I finally got around to pulling the bearing caps, not only were the bearings still nice and oily, there was enough oil left in the passages to drip off the crank ! That kind of staying power has got to be a boon for engines that are only driven in the summer.
Also seemed to work very well in my Chevy V6. Though I never had the pan or heads off, the rocker area looked nice and clean after 120,000 miles or so on the VR.