I have a stock CT26. Bone stock but Dynamic Turbo is upgrading it for me. With a good Boost controller 425 to 450 Horses in a heartbeat! One thing I dont like about CT26 is. It is an Activator Turbo.
At $550 I would check with GGraddy Turbo.
I also have a spare Engine. It is going to my 85. With the right setup 500 Horses not a problem! Thermo Shield at Nebraska Ave. did the fabrication on my Turbo Headers. With this Headers an Upgraded CT26 and a 3 straight Pipe 330-350 Horses. With an upgraded Intercooler you might get 30 more Horses!