spark plug question

[ForceFedZ]

Hello all! new to this forum so i thought id start out with a warm greeting. just wondering what type of plug you guys with AFR heads are running. I need to put my mods in my sig but the main mods are AFR 195 LT4 heads, GM 847 cam,LT4 intake,42 lb injectors, full exhaust, and full MSD ignition. all this is on a 355 block with roughly 11:1 comp. Gonna be getting a dyno tune n the near future and I want to change the plugs over to a good quality plug. I will not be spraying the car..........yet... right now Im running Autolite 3910's but i dont know the heat range of these. Do I need to go hotter than stock? No one around here can seem to help me pick the correct type so any help will be apprecited. Thanks

[Masoch]

I'm not running AFR (LE2, rather) but I have had success boosting with NGK and hear their plugs are top-notch in standard applications too. Stock gapping should be fine to my knowledge since you have no plans for N02.

[Z28pr0jekt]

Ah I cant search it now because the computer I'm on sucks ass but there is a thread on either cz28 or ls1tech that gives the ranges and specs of what plugs you should use for different types of heads and stuff on lt1s and on ls1s... try searching on those.. it was a bit down in the thread (nitrous forum section i think so you can narrow the search to that) and it was someone quoting somebody else

[Speed Density]

3910 is a #9 plug, thats cold.

Go pick up some 3924's and your set.

[ForceFedZ]

so the 3924's are a stock heat range or are they a little hotter?

[LT4SS]

i'm running NGK TR6 part number 4177 in my AFR LT4's, but i'm spraying mine. on a NA i'd run a TR5 or TR55

[Speed Density]

i'm running NGK TR6 part number 4177 in my AFR LT4's, but i'm spraying mine. on a NA i'd run a TR5 or TR55

Bad idea, TR6's are terrible plugs to spray on with the options there are out there. Blow torch, sir? Pick up some 3935's, gasket and heat range 7. Perfect for an LT1 on gas.

OP, 3924 is a heat range 6 respectivley. Projected tip too.

[ForceFedZ]

Yeah i ran TR6's on my car when I used to run a blower. Think they were 1 possibly 2 heat ranges colder than stock. Great plugs for stock heads but an angled seat design. AFR heads call for a flat seat w/ gasket Found that out when I had my car dynoed the first time. Car skipped like shit. Thanks Speed Density for the help! Ill go pick up a set of 3924's and give em a shot

[Speed Density]

There are two versions:

AR3924 - http://www.power-21.com/AutolitePower21i/PartDetail.aspx?b=A&pn=AR3924

3924 - http://www.power-21.com/AutolitePower21i/PartDetail.aspx?b=A&pn=3924

Onces a nickle plated 'racing' plug and the other is traditional but both are non-projected and #6.