Best plug for LT-1

John Nechiporchik · 07-30-2013, 09:07 PM

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.

Ed Wright · 07-30-2013, 09:22 PM

104 Autolite.

Rob Petrie E395 · 07-30-2013, 09:43 PM

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?

curtis hieb · 07-30-2013, 10:56 PM

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

Ed Wright · 07-30-2013, 11:11 PM

Quote:

Originally Posted by Rob Petrie E395

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?

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.

Mike Taylor 3601 · 07-31-2013, 08:54 AM

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

John Nechiporchik · 07-31-2013, 09:26 AM

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

07-30-2013, 09:07 PM	#1
John Nechiporchik Member Join Date: Mar 2007 Location: Grosse Ile Mi. Posts: 315 Likes: 84 Liked 12 Times in 6 Posts	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.

07-30-2013, 09:22 PM	#2
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Best plug for LT-1 104 Autolite. __________________ Ed Wright 4156 SS/JA

07-30-2013, 10:56 PM	#4
curtis hieb Member Join Date: Oct 2008 Posts: 125 Likes: 5 Liked 9 Times in 8 Posts	Re: Best plug for LT-1 I use NGK with larger gap can't remember the number but can get it for you.

07-31-2013, 08:54 AM	#6
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,361 Likes: 333 Liked 279 Times in 96 Posts	Re: Best plug for LT-1 We used the crap out of NGK's for a long time with no problems. Mike Taylor 3601

07-31-2013, 09:26 AM	#7
John Nechiporchik Member Join Date: Mar 2007 Location: Grosse Ile Mi. Posts: 315 Likes: 84 Liked 12 Times in 6 Posts	Re: Best plug for LT-1 Ed, Are you using the 104 or the AR 104(racing plug)?

07-30-2013, 09:43 PM	#3
Rob Petrie E395 VIP Member Join Date: Dec 2007 Location: Woodlawn IL Posts: 1,092 Likes: 162 Liked 216 Times in 77 Posts	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?