sparkplugs

[mtb]

Just spoke to rob Robertson at v8devopements who rebuilt my 3.9 engine 900 miles ago
Just noticed e has used ngk b6 where I have always used b7s he recons the b7s soot up to easaily and would even drop to b5s l run a holley carb on this motor which he says makes no odds also the emmisions on the mot are as good as when it was injected after he set it all up.

Mike

[keatsie]

any modification that does not alter the overall compression ratio will not usually necessitate changing plug types or heat ranges. Unless you have increased the power with the carbs in which case you will have increased the heat and since spark plugs must remove heat a colder heat range spark plug might be a good idea along but I wouldn't go lower than B6 personally but others more knowledgable may have better suggestions.