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Discussion Starter · #1 ·
Sorry for the simpleton post, but Im sure you guys have gotten used to it by now. lol Im heading to the dyno and wanted to throw on a new-er Opti and some new plugs. Just want to make sure Im gettin the most out of it.


Motor is :

SR 396 LT1 block 11.75 comp
AFR 210 LT4 heads (flow numbers should be attached)
Stock opti with MSD cap n rotor, MSD coil and wires also
Autolite Racing AR 3923 (gasket style plugs)
#42 Green Top Injectors


Any advice is welcome. I was thinking about .45 or so. I believe stock is around 50 but I could be wrong and Ive seen nitrous folks go down to around a .35, so I figured Id settle in the middle.


Thanks again for any help,
ZACH
 

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Hi Zach my golen 396 i was told to use autolite 104 gapped AT.050.I hope that helps.
Paul.
 

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My preference for your setup would be .040, but anything between .035 and .050 is good.
Smaller gap = less chance of misfire due to some part in the ignition system not being totally up to snuff.
For dyno runs and high power operation, there is so much mixture motion there's really no benefit with a wider gap. Wide gaps are good for fuel mileage at low MAP/low RPM conditions.
 

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I gap my 409 at .030. I run the AC-Delco part that corresponds to the Autolite 104. My long-time GM mechanic refuses to put Ford stuff on my Impala. He says their plugs are junk, but I've had no problem with either.:p
 

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Discussion Starter · #5 ·
Thanks alot guys, for all the help.
Ill go ahead and listen to Pat.

As for the plugs, Im not even too opposed to changing the kind of plugs, Im just using the ones AFR said should work.

ZACH
 
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