How heavy are you going to tow?
What do you mean by "slightly modified" ?
You will get warm towing on a stock hy9 turbo (01 truck or 01.5?) You will also slip the transmission at that level.
Its not excessive, but you will have to keep an eye on the EGTs. You have far more control with your right foot then you do anything else on the truck. That is how the 12v guys have done it for years. Just keep that in mind, and you will be fine.