Hey Kevin,
Are your plug ends straight or 135 degree.
I have trouble with mine, they are ICE Ignition 135 degree and have heat socks.
One of them is very close!
Never thought about straight, 135 or 90 degree.
I reckon a mix and match for each cylinder may be the best.
I’ve got JBA1650 headers.
I’ll look into that, that’s for the thought.
Cheers Phil.