3.9 L V-8 with mechanical distributor, 1994 Disco.

I just got a kit from PowerSpark in England. Cost around $75 with FedEx shipping, and arrived in 2 days after I ordered it. US suppliers were either out of stock or wanted many hundreds of dollars. I have wanted to do this mod for a while, now I'm stoked.

They have a more expensive option that includes a new connector from the amp to the coil circuit, but I already have one because I damaged the wires when cranking (

Amplifier relocation kit from UK
years ago) after I forgot to plug it in (ouch).