I've put Nitros on one car. It was only a 50 horsepower shot. I read up on it before & the main thing is not to put too big of a shot on a engine. Like Cam said, you'll need to get more gas to the engine. So a electric fuelpump or a hi-performance mechanical pump is needed. If I'm correct NOS leans the engine out. This is where people get into trouble with pistons coming apart on them. If you have a good engine let's say mildly hopped-up then you could go 100hp.
But, say the engine can handle the extra power. What about the transmission & rearend? Everything needs to be in good condition.
Lancaster, South Carolina
66 Coupe, 302, Auto, 3.25 gears. [color:red]Candyapple Red</font color=red> with White Pearl Stripes. Cragars. http://web.infoave.net/~ronniek