John
The longer and hotter spark you have the more complete the combustion will be. As far as 7-1 compression ratio I believe most of the sixes being built today that the owner would consider a hot ignition for will have a higher compression ratio. I agree that if you are building a 216 with splash oiling you are fine with a stock ignition, if you are building a 250/292 with higher compression then a modern high voltage ignition is better. You talk about things you tried back 25 or 30 years ago but have you built and drove a modern engine with a complete MSD ignition and plugs gapped at .080? The improvments in high performance ignitions in the last few years is almost beyond compare. I my case my inline is built for touring on any type of road in the country at any speed I wish to drive. I hope when my wife retires in a couple of years to travel the entire country and visit with some of the people I have only typed at. With that thought in mind I am striving toward a six that performs like an V8 and will still get a 25+ MPG average with the A/C on. I'm almost there and with the changes I've made this winter I hope to be there this summer. I agree also that if you are only driving your vehicle 20 or 30 miles a week on low speed roads you don't need to modify anything on the vehicle, unless you want to make it a safer better performing vehicle and if that is the case spend what you can afford to build the car/truck of your dreams.
