gn1 alum. heads

[Crazyx4]

what spark plug should I use?

 

[Major Nutz]

what spark plug should I use?

I use autolite 103s for street duty and 104s for the track.

 

[whitehot1]

I've used NGK TR5's and Autolite 104's in my engine for street driving only and both work well.

John:smile:

 

[Crazyx4]

I have ac delco rapid fire #1. does anyone run a rapie fire plug?

 

[whitehot1]

I have ac delco rapid fire #1. does anyone run a rapie fire plug?

I've probably tried every plug type there is and never seen any advantage to any of them over the standard type plugs like i mentioned above. So here is your chance to learn from my experience and for you to save your money.

Here is a little list of the plugs i've tried over the years with no noticeable improvement in performance, the only real difference is they just cost more.

autolite platinum
split fire
rapid fire
accel
iridium
bosch platinum
bosch platinum +4

John :smile:

 

[Audie1]

what spark plug should I use?

Whatever ones you use, just make sure that they are the correct length plug for the GN1's, such as the Autolite 103 & 104's. I bought my current GN about 6 years ago and always changed the plugs out with the type that was in it (R42TS). I could not figure out why I was not making the HP that I should with my set up. One of the this Forum's Members told me that I was using the wrong length plugs. Sure as hell, I switched over to Autolite 103 which are about 5/16's of an inch longer (to make up for the thickness of the GN1 Heads). I dynoed it again and instantly picked up 42 more HP at the wheels!!! So I learned something....felt kinda dumb, I'm glad I found out.

 

[STERN FLOW]

103 Race 104 Street 104 Is Hotter.
If You Run 10.50 Or Faster You Need A Colder Plug.
Like Autolite Ar3932 Witch Is A Racing Plug With A Gasket.
Not A Tapered Plug

 

[fastdon3]

i use the 103s good for racing

 

[Major Nutz]

103 Race 104 Street 104 Is Hotter.
If You Run 10.50 Or Faster You Need A Colder Plug.
Like Autolite Ar3932 Witch Is A Racing Plug With A Gasket.
Not A Tapered Plug

I guess i got them backwards. Sorry about the mix up.

 

[Crazyx4]

thanks for all the help

 

[fastdon3]

no problem that what were here for

 

[Under Pressure]

what gap on the 103's?

 

[KevinB]

I use the NGK R5671A's. Heat ranges vary on tune and weather. Usually 9's but sometimes as hot as a 7 (NGK's are opposite of other plugs, hotter plugs have the lower numbers.) I gap mine at .030 with the stock ccci.