I am currently run a cammed car 227/233 .560&.569. and mild head work, all other bolt on's too. I am debating putting a shot of nitrous on it later this summer. I currently run the NGK tr55's. For the nitrous, I know the golden standard is the tr6's. I am going to change my spark plugs here in the next few days, and even with headers, it still sorta takes up some time...about 1 hour. Will my motor only performance suffer from going to a colder plug? Some say that head/cam cars should run a colder plug, but I havent changed my heat range so far. I already have the MSD 6al, and would gap the plugs at .35-.40. Any input? Can you run the tr55's with nitrous with no ill effects?

 

Nah, Your "motor only" performance won't suffer going with a colder plug(like the heat ranges were talking about here anyway ).....Iv'e run the TR55, TR6's, autolite 104's, and am now currently running the autolite 103's that I like the best(they seem to last the longest for my current set-up and read the most even, not to mention they're cheap and available pretty much everywhere)....I gap them at 35-38 thou for dual purpose (NA and bottle) and they're about perfect for both(except I'd go 50thou + on the gap if I wasn't running the bottle at all)......some guys run the TR55 with small shots, but I really can't see the sence, since a slightly colder plug has really no disadvantages in this situation....just important safety advantages while running the bottle