Best plug for LT-1
 

Recently Purchased stocker (350 LT1 fuel inj.) has AC Delco Rapidfire #3 plugs.
What are you guys using in this combo?
Typically I've used autolites in my previous BBC engines....but this is new territory for me.
Thanks.

Re: Best plug for LT-1
 

104 Autolite.

Re: Best plug for LT-1
 

Ed
There are two Autolite 104 plugs. There is the standard which is .032 gap and a alternate desgin which is .044. I used the .032. Should I have used the other? That seemed like alot of gap to me even with MSD ignition. Did I guess right?

Re: Best plug for LT-1
 

I use NGK with larger gap can't remember the number but can get it for you.

Re: Best plug for LT-1
 

I set mine to .045". I run my MSD stuff off two 16 volts batteries.

As for NGK, I have had to pull so many new NGK plugs out of customer's cars brought in for dyno tuning, I would not put them in my lawn mower. Kids would say "I never heard it miss like that before." "You never stood at the back of the car, running at WOT, in a tin building before." A new set of Autolites always fixed them. Had a box full of those things on one of those work benches in the middle of the shop area. I know they aren't all bad, but too many for me to ever use them.

Re: Best plug for LT-1
 

We used the crap out of NGK's for a long time with no problems.
Mike Taylor 3601

Re: Best plug for LT-1
 

Ed, Are you using the 104 or the AR 104(racing plug)?

Re: Best plug for LT-1
 

Plain old 104.

Re: Best plug for LT-1
 

Ed, Thanks for the info. I'll pick some up today. Do you index them?

Re: Best plug for LT-1
 

Sometimes. Have never found anything there. Can't hurt.
Used to index them in my old C/SM Camaro back in the '70s, straight plug heads and big domes. To prevent knocking them shut. LOL