Its my personal believe you are asking for trouble with thoose kits. car nitrous is a combination of nitrogen and oxygen with a little sulpher dioxide int he mix to soften the hit a bit and also make it non wifable. the oxygen is what makes thew power , the nitrogen is just a filler. Nitrous is not like some magic power additive its just increases the oxygen content of your intake charge. It is very fuel sensitive. as u know too much air and not enough fuel = a lean condition. air is 21% oxygen . Nitrous is higher , i think its 38% maybe. anyway its a good way to SMOKE a motor dicking around with a bullshit kit. on a non race vehical I would be doing the computer , air intake , exhaust and tuning and not worry about shooting juice. what are you going to gain from it. compaired to what it can do. It is no designed nor is it anything like u see in the movies. Systems are tuned and tuned again even to changing track and air conditions present in racing..

So not only will you not get a huge gain from some shitty kit you risk your engine. for what? are you going to put a mid 14 sec truck into the high 13's? it will also raise your cylinder preasure , put un needed stress on pistons ( should be forged) also stresses the rods and the crank.

to properly run nitrous you should have theese impliments installed

wot activation switch
window switch
low fuel preasure cut off
be in control of your timing(2 degrees must be retarded for every 50 horse of spray)
a stand alone fuel system to support the nitrous system
purge valve
bottle heater ( to maintain proper bottle temp to keep proper operating PSI of the system)
a blow down tube from your bottle valve out of the car if the safty blow off pops
you may need to try different heat range plugs to keep them firing optimaly in a more fuel and air rich enviorment with out fouling or burning out.

so now u bought an over priced kit ( zex) 500 bucks that falls short of any sort of viable system and need to buy another grand woth of stuff to properly run nitrous and well hell u might as well save up for a blower and always have the power. Id go into more detal on number of seconds of use per hp and size bottle. but searching nitrous turning u can find that. Again I reinterate that this fad is not all that great of an option for stock rides , espeially ones that arent performance orientated. gears and converter make a difference also. as does the pattern on your cam. blowing 125 horse shot into a mostly stock truck with bolt ons definatly will not net you 125 horse to the wheelsyour mush stock converter is going to soak up some as well as the truck dtive train and the non performance oriented gear ratio.

Just my 2 cents