Get a dial back timing light (budget Actron is what I use) and a vacuum/fuel pressure gauge setup (like $30 from Harbor Freight). A compression tester is a bad idea either, but the 1st two are necessities for tuning. And not old school tuning either. I use all 3 of those tools regularly, and if you dig into my builds and posts NONE of them are carb'd with a distributor. But all of the same principles apply. Vacuum leaks and timing numbers don't care if you have a carb from the 80's or current EFI.
Those 3 tools will set you back $100-140 depending on what you buy and where you buy them. But they are absolutely invaluable. Once you understand how to use them, which is not difficult, you'll begin to understand all of my previous posts.