861, 868, 947, J8, J8C, J8J, J17LM, J19LM, QJ19LM, RJ19LM. Premium quality copper core electrode spark plug for improved conduction and reliability. Valley Forge GL2, GL3, GL4. 741, 1147, 3110, 3410, 3841, 4146, 4861, 4864, 5798, 6150, 7931, B2LM, B2-LM, B2LMY, BR2LM, B4LM, B4LM BL1, B4LMY BL1, B2, CS1.