I ran into the same problem when I went from the rusty/crushed headers the car came with, to a set of ceramic coated Hedmann's. The top pipe (#3) on the new headers is angled back 3/4" closer to the head than the previous set, rather than parallel-ish. I've got a set of those braided cloth heat shields over the straight plug wires for now. I'm going to try angled plug boots when I get new wires. Not perfect but it's getting me by for now. I think the only good solution is a set of TTI or other headers that don't run that #3 pipe over the top.
Vibrant Performance Heat Protect Flexible Sleeving 25890
