Spark plug question/Nitrous

[nos90gt]

I have a Spark plug question. I am spraying 150 shot. What plug should I run, and what should the gap be set to? Motor is a GT-40 crate motor/carbed,MSD 6AL with gt-40 iron heads.
Thanks for any help you can give. Thanks, Scott
[email protected]

 

[RacEoHolic330]

autolite 3923 at .035

 

[nos90gt]

Thanks man

 

[blksn955.o]

I ran the autolight 3923's on my gt40 iron heads...they are not correct they are for an Alum. head. They have a wider area (and some along those models have an alum. gasket that has to mount flush with the head) and will not seat along the plug hole due to the iron heads tapper at the plug hole.

I run a NGK TR6 its one range colder...stock is a TR5 and 2 steps colder is a TRi7 it is only avail. in an irridium(sp? no friggan idea) plug, as notice the "i" in the name. This is the correct plug for the iron gt40 heads.

a good gap is .035 like said above.

 

[nos90gt]

Right now I am running Ac's-R42LTS at .035

 

[Scorcher2005]

so long as you get a copper plug thats a step or 2 colder than stock you'll be fine. I've actually ran the stock heat plug (Autolite 25s) w/ the stockish gap of .045-.05 w/ my 125 shot and it was fine