Darts what plug?

[Neil350]

This is from the spec sheet: Angle .750” reach, gasket, which seem to be same as AFRs/Trick Flows/Edelbrocks on the list I found on CZ28.com. So any from the chart on CZ28.com for those heads should work with these Darts correct? The recomended plug from Dart is a AR3934, so far it looks like the NGK 7942s are the winner, same dimensions as the NGK, 14mm thread, .750 reach, gasket seat, 5/8 hex.

[jakesz28]

The Autolite AR3934 are a heat range of 8. They are non projected tip , so that is the right choice. Depending on the total amount of power you may need to run an Autolite AR3933 which is a heat range 9. With Autolite plugs the lower their number the colder the plug. With NGk's a 11 is colder then a 7.

Autolite NGK
3931--- R5671A-11
3932 ---R5671A-10
3933--- R5671A-9
3934--- R5671A-8
3935--- R5671A-7


I'm not sure what the 7942's are? But this is the way I cross referenced them. I like the fact that the that the autolite plugs are shorter from the seat to the tip of the spark plug connector. Leaves a little more room around the headers if needed.

[Neil350]

Thanks for the list Jake, The NGK Part # is R5672A-10, heat range wise they match 3932. What the difference between a R5672A and R5671A is I dont know, but they share the same heat range of 10.

[jakesz28]

R5672A-10 is about the same as an autolite AR50. I'm not quite sure without actually having one but that might be a projected tip.