So, we've ruled out NOS as a solution to your towing problems. But I don't know why some thing a little 30 shot like you were talking is all that bad? Back in my car days I ran a 75 shot through an otherwise stock v6 mustang just for shits and giggles. I ran what you call a "wet kit" that supplies the extra fuel needed through a separate line and nozzle. You "tune" it once on the dyno by selecting the proper fuel jet to get the a/f right when you're spraying. No other tuning needed to the car. Ran probably 100 bottles with no issues. After I sold my v6 mustang we put the nitrous kit on a Geo Metro. 75 shot...I imagine we just about doubled the hp that thing had. We tried to blow it up, but it just kept running. It had no traction from a stop, but would pull like a freight train from a 30 roll. Completely gutted interior, every ounce of extra weight we could get rid of was chopped, cut, ground off. That little Geo embarrassed many mustangs, camaros, and other fast cars on the 270 loop. Shit, I might just go by another one of those for the hell of it to have some fun with.