C5kid

iTrader: (12)

I found this awhile back on Corvetteforum...

LS1 Stock and AFR
Thread – 14mm
Reach - .708”
Socket – 5/8 hex
Seat - Taper
Stock Heat Range: 5
Gap: .060
Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Autolite 764; Denso IT-16 (stock number 5325)

(one step colder)
Heat Range: 6
Gap: .035 - .038
Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Autolite 103; Denso IT-20 (stock number 5326)

(two steps colder)
Heat Range: 7
Gap: Consult
Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Autolite AR94; Denso IT22 (stock number 5327)

(two and a half steps colder)
Heat Range: 8
Gap: Consult
Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (part number 3691); Denso IT-24 (stock number 5328)

(three steps colder)
Heat Range: 9
Gap: Consult
Plug: NGK R5724-9 (stock number 7891); Autolite AR93; Denso IT-27

(four steps colder)
Heat Range: 10
Gap: Consult
Plug: NGK R5724-10 (stock number 7993); Autolite AR92


LS1 w/ Edelbrock and Dart Heads
Thread – 14mm
Reach – 3/4”
Socket – 5/8 hex
Seat – Gasket

Stock – MFG Recommendations: approx under 9:1 compression
Heat Range: 4
Gap: Consult ignition mfg.
Plug: NGK FR4 (stock number 5155); NGK BKR5EIX (stock number 6341); Autolite 3926; Champion RC12YC (stock number 71); Denso IK16 (stock number 5303)

MFG Recommendations: approx 10.5:1 compression
Heat Range: 5
Gap: Consult ignition mfg.
Plug: NGK FR5 (stock number 7373); Autolite AR3924 (Racing Plug); Autolite 3924; Champion RC9YC (stock number 2075); Denso K20PR-U (stock number 3145); Denso IK20 (stock number 5304)

MFG Recommendations: approx 11:1 compression
Heat Range: 8
Gap: Consult ignition mfg.
Plug: NGK R5672A-8 (stock number 7173); Autolite AR3911; Champion C63YC (stock number 796); Denso IQ24 (stock number 5314)

MFG Recommendations: approx 12:1 compression
Heat Range: 9
Gap: Consult ignition mfg.
Plug: NGK R5672A-9 (stock number 7405); Autolite AR3910; Champion C61YC (stock number 785); Denso IQ27 (stock number 5315)

MFG Recommendations: approx 13:1 compression
Heat Range: 9 - 10
Gap: Consult ignition mfg.
Plug: NGK R5671A-9 (stock number 5238); Autolite AR3933; Champion C59CX (stock number 296); Denso IK27 (stock number 5312)

MFG Recommendations: approx 14:1 compression
Heat Range: 10
Gap: Consult ignition mfg.
Plug: NGK R5671A-10 (stock number 5820); Autolite AR3932; Champion C57CX (stock number 295); Denso IK-31 (stock number 5321

DannoWS6

iTrader: (5)

I had TR55's (gaped .050) and went to TR6's (gaped .045) last time. Probably 10.8-10.9:1. No problems, car felt just as strong as before. They do say to drop 1 step colder every 100hp.

I'd say go with the TR6's. My tuner recommends them as well for a h/c car especially with higher CR.