Hi
Im having trouble getting my nos up and running, im getting a hit then a bad missfire and loss of power.
I think the pugs may be the problem, im wondering what plugs you's are using.

350 chev \125 hp power shot kit

 

a cooler heat range or two. part #'s are head specific. avoid any platinum, or fancy electrodes.

 

the heads are 3890462 double hump fuelies, all i could find out is there of a 64 to 68, i ended up using ngk b6s's as that's all i could get hold of, wich i think are the standard heat range.

Im not gitting a missfire now so they must be ok.

The nos doesnt seem to do a thing in the upper rpm should i be getting any increase in power up there with a 125 hp kit?

 

you might want to recheck the rest of your ignition
try gapping the plugs down to .032" or so
but make sure the rest of your ignition system is up to par first

stock ignition systems sometimes have a hard time coping with the increase in cylinder pressure and often cause the misfire especially at high rpms
jimbo

 

ditto, what jimmbo said. if decreasing the gap helps to reduce or eliminate the missfire, then it is very likely that the ignition cant ovecome the cyl. pressure.

BW

 

I'd go two steps colder on the plug.