4.10's and 35's don't make for a good drag racer. Trust me

I wouldn't be concerned with installing a turbo, even if the history of your truck is unknown. All of the mods you have done, or are planning have to do with getting more air in and out. My truck has over 250K miles on it and I'm in the process of a turbo install. I'm figuring that it should run cooler and not work the engine as hard which will prolong its life. And if it don't, then I'll upgrade to something else.. 6.9? 5.9? 6.7?

Stan's Headers used to sell an IDI header. Not sure if they still do.

Jason