Colder plugs can help with preignition, but usually they aren’t needed unless you’re boosted. Have you asked Justin for his recommendation? My Whipple instructions stated for me to drop 2 heat ranges and go with NGK TR7’s but when I was having some rough running issues he told me TR6’s would be better in his opinion. TR5 are stock for my 6.0. If TR5’s are listed as compatible for a 6.2 then you could try the TR6’s. The letters after TR6/TR5 are the type, IX are iridium, no suffix is regular type, etc. I run the regular TR6 on my blown 6.0.
Edit: I looked up plugs for an 08 Tahoe with a 6.2 on Rockauto and they list the NGK 2238 which shows an alternate p/n as TR5 so you can run the TR6’s. Since it’s an experiment you can just try the regular TR6’s since they’re only about $1.50 each if you want. That’s the part number you need to ask for, or TR6IX if you want iridium. Don’t let them ask you for the make year and engine or they’ll say they’re not the right plugs for you.
Edit: I looked up plugs for an 08 Tahoe with a 6.2 on Rockauto and they list the NGK 2238 which shows an alternate p/n as TR5 so you can run the TR6’s. Since it’s an experiment you can just try the regular TR6’s since they’re only about $1.50 each if you want. That’s the part number you need to ask for, or TR6IX if you want iridium. Don’t let them ask you for the make year and engine or they’ll say they’re not the right plugs for you.
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