Thats the theme with turbo builds. Lol. They seem like cheap, quick, easy HP, but these builds take a lot of time!
My turbo dart has a Continental 10" 3000 stall turbo converter. It took them a lot of tries to get it perfect since boost messes with converters. This was in the 90s and over the years they have a good grip on the turbo set ups. I highly recommend them, they are in Inglewood. Every converter we have bought since has been spot on and their customer service is excellent!