For what it is worth this is my advice. The proper sizing of the turbo is VERY important. especially if you are buying or building a cheaper Ebay style kit. Turbo too small spools to quick hard on turbos, and the parts going through an engine when the impeller lets go is very bad. Turbo too big no power down low lots of lag, and only makes boost at higher rpm's. Lots to read on the internet this page will give the basics. https://www.garrettmotion.com/racing-and-performance/choosing-a-turbocharger/ If you are doing an older style engine some way to control the timing with a computer is a must. Plus a computer controlled boost regulation of some kind as well. Intercooler always makes more power less detonation.