If the OP doesn’t have the money for forged pistons he shouldn’t be considering a boosted towing application. I wasn’t assuming his skill level, he admittedly said “Help out a lost guy because I've always been an N/A engine type of guy and the land of boost is foreign to me.” This most likely means tuning a forced induction engine as well. Turbo sizing is much more than “too big” or “too small”, read and understand a few compressor maps and you’ll understand that. You do not want boost early in this application, you want to be able to drive in light load situations off boost and have the power when you need it, so no not “early by compare”, later is better. So sizing larger than you would for a street car application is important. A 360 with 70mm turbo might be right in the 70% efficient zone in a 3000lb dart but put it in a 4500lb truck with a trailer behind it and all of the sudden it’s in surge. Defining a turbo by “race car sized” is ridiculous. That same 70mm turbo on a k series Honda might be appropriate if you were racing it.
