[D13]

If you're spraying below 4000RPM you're not all the way up in the motor's power band, and already well past the flash point of the converter. Remember, the 325hp engine gets that power up at 5000RPM +. So you won't feel as hard a hit (since the converter will keep the engine from flashing up) but more of a steady push. Unless you're adding fuel you won't get the full value; remember, the point of nitrous is to add O2, allowing you to add more fuel. The shift kit will help tremendously, but a chip that adds fuel and adjusts trans pressure and shift points would probably help more.
FWD's spin a lot easier than a RWD, assuming the suspension is already loaded, which it should be if you're turning 4K before spraying.

BTW my 99 Xcab weighs 5400# with 1/4 tank fuel. Compare that to my 72 1 ton which went 4500# with a 402, or your 3200# honda, remembering that F=MA or A=M/F. It takes a lot more force to get the same acceleration out of a big truck. Also it's a lot less noticable in a bigger vehicle. 70 in a Chevette feels like 120 in a Caprice.