There is a company in Colorado that has certification for LS/LT swaps into a few Cessna models. They've essentially made it a start and go. No magneto checks, or run up test.
I watched the video on their website and you don't need to do a run-up unless you are using leaded fuel, like avgas. The reason is that you can get lead built up on the spark plugs with leaded fuel, so you do a run-up to get everything good and hot, which will usually melt the lead off the spark plugs or give you a clear indication that you can't develop full power. Auto gas doesn't have lead.